Data Visualization and Cholera: An Unexpected Connection
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Data Visualization and Cholera: An Unexpected Connection

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Radial chart london cholera

Data Visualization and Cholera: An Unexpected Connection

Necessity is the mother of invention, and in the mid-1800s, understanding the spread of cholera was a matter of life and death.

Ruthless Efficiency

Cholera was a ruthlessly efficient killer, with both rapid onset and severe symptoms. By the time the disease made its way to London and New York in the early 1830s, hundreds of thousands of people had died across Europe, Africa, and Asia.

Not only our personal and national interests, […] it may be said without exaggeration, [that cholera] concerns the whole human race.

– Thomas Whiteside Hime

Needless to say, the human race was concerned. Thanks to high-speed printing press technology, daily newspaper circulations were rising dramatically, and this allowed journalists to experiment with new reporting techniques, including charting data.

cholera line chart

At the time, the chart above was such a novel approach that it required four paragraphs to explain how to read it. People of that era were simply not used to seeing data in a visual form. At a glance though, the chart is extremely effective at communicating a grim message: cholera had ravaged New York City over the summer of 1849.

Despite the concerted push to eradicate the disease, the medical community was still largely in the dark about how to prevent future outbreaks. Because doctors could treat numerous patients without falling ill, it was assumed that a miasmic environment (i.e. slums, densely-packed housing) was causing the spread.

Data Viz in the Time of Cholera

Today, we have tools that allow us to map just about anything, but in the mid-1800s, mapping data was still an innovative concept.

As early as the 1830s, geographers began using spatial analysis to study cholera epidemiology. The heat map below shows which sections of Paris were hardest hit by a recent outbreak of cholera.

1832 cholera map paris

In 1854, Dr. John Snow was convinced that cholera was spreading via tainted water and decided to display neighborhood mortality data directly on a map. This method clearly revealed a cluster of cases around a specific pump.

john snow cholera map
View the full version of the map here

The result is one of the most influential maps in modern history.

In addition to the real-world utility the map provided in helping physicians understand how cholera was spreading, it also exemplified a seismic shift in thinking that opened up new avenues for data to be analyzed and displayed.

Despite the tragic circumstances of the time period, we can be thankful that the urgency of the situation allowed the world’s pioneering researchers, journalists, and physicians to experiment with new data visualization techniques to better understand the world.

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Automotive

The Most Fuel Efficient Cars From 1975 to Today

This infographic lists the most fuel efficient cars over the past 46 years, including the current leader for 2023.

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The Most Fuel Efficient Cars From 1975 to Today

When shopping for a new car, what is the most important factor you look for? According to Statista, it’s not design, quality, or even safety—it’s fuel efficiency.

Because of this, automakers are always looking for clever ways to improve gas mileage in their cars. Beating the competition by even the slimmest of margins can give valuable bragging rights within a segment.

In this infographic, we’ve used data from the EPA’s 2022 Automotive Trends Report to list off the most fuel efficient cars from 1975 to today.

Editor’s note: This is from a U.S. government agency, so the data shown skews towards cars sold in North America.

Data Overview

All of the information in the above infographic is listed in the table below. Data was only available in 5-year increments up until 2005, after which it switches to annual.

Model YearMakeModelReal World Fuel Economy (mpg)Engine Type
1975HondaCivic28.3Gas
1980VWRabbit40.3Diesel
1985ChevroletSprint49.6Gas
1990GeoMetro53.4Gas
1995HondaCivic47.3Gas
2000HondaInsight57.4Hybrid
2005HondaInsight53.3Hybrid
2006HondaInsight53Hybrid
2007ToyotaPrius46.2Hybrid
2008ToyotaPrius46.2Hybrid
2009ToyotaPrius46.2Hybrid
2010HondaFCX60.2FCEV
2011BMWActive E100.6EV
2012Mitsubishii-MiEV109EV
2013ToyotaiQ EV117EV
2014BMWi3121.3EV
2015BMWi3121.3EV
2016BMWi3121.3EV
2017HyundaiIoniq Electric132.6EV
2018HyundaiIoniq Electric132.6EV
2019HyundaiIoniq Electric132.6EV
2020Tesla3138.6EV
2021Tesla3139.1EV

From this dataset, we can identify three distinct approaches to maximizing fuel efficiency.

Downsizing

Prior to 2000, the best way for automakers to achieve good fuel efficiency was by downsizing. Making cars smaller (lighter) meant they could also be fitted with very small engines.

For example, the 1985 Chevrolet Sprint was rated at 49.6 MPG, but had a sluggish 0-60 time of 15 seconds.

Hybrids

The 2000s saw the introduction of mass-market hybrid vehicles like the Honda Insight and Toyota Prius. By including a small battery to support the combustion engine, automakers could achieve good MPGs without sacrificing so heavily on size.

While the Insight achieved better fuel economy than the Prius, it was the latter that became synonymous with the term “hybrid”. This was largely due to the Prius’ more practical 4-door design.

The following table compares annual U.S. sales figures for both models. Insight sales have fluctuated drastically because Honda has produced the model in several short spans (1999-2006, 2009-2014, 2018-2022).

YearInsight SalesPrius Sales
2005666107,155
2006722106,971
20073181,221
2008-158,884
200920,572150,831
201020,962140,928
201115,549136,464
20126,619236,655
20134,802234,228
20143,965207,372
20151,458184,794
201667136,629
20173108,661
201812,51387,590
201923,68669,718
202015,93243,525
202118,68559,010
20227,62833,352

Source: goodcarbadcar.net

The Prius may have dominated the hybrid market for a long time, but it too has run into troubles. Sales have been declining since 2014, even setting historic lows in recent years.

There are several reasons behind this trend, with one being a wider availability of hybrid models from other brands. We also can’t ignore the release of the Tesla Model 3, which began shipping to customers in 2017.

Electric Vehicles

We’re currently in the middle of a historic transition to electric vehicles. However, because EVs do not use fuel, the EPA had to develop a new system called MPGe (miles per gallon of gasoline-equivalent).

This new metric gives us the ability to compare the efficiency of EVs with traditional gas-powered cars. An underlying assumption of MPGe is that 33.7 kilowatt-hours (kWh) of electricity is comparable to the energy content of a gallon of fuel.

The most fuel efficient car you can buy today is the 2023 Lucid Air, which achieves 140 MPGe. Close behind it is the 2023 Tesla Model 3 RWD, which is rated at 132 MPGe.

Check out this page to see the EPA’s top 10 most efficient vehicles for 2023.

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