The Winnipeg Free Press is tracking the number and results of COVID-19 testing in Manitoba, as reported daily by the provincial government.
The percentage of tests that are positive, referred to as the test positive proportion by the province, shows the infection rate among those tested for the virus. Despite looking noisy and erratic, the value remains below two per cent.
Another important statistic is per capita value, which helps compare something among groups of different sizes. Generally speaking, more populous provinces will have more tests, positive cases and deaths, simply because there are more people. To effectively compare provinces with different populations, we determine how many tests, cases and deaths there are for each person in the province. Per-capita data is usually reported per 100,000 people to avoid using tiny decimal values.
Tracking the growth of reported COVID-19 cases in Canada, from the fiftieth case onward, illustrates possible trajectories based on other provinces that are further along the COVID-19 timeline. Manitoba, along with other less populated provinces, follows a gentler curve.
This chart uses a logarithmic, also known as a log, scale on the y-axis to plot case counts for each province.
Logarithmic scales, which are exponential as opposed to linear, are useful for displaying and analyzing data that covers a wide range of values. Using a log scale allows the chart to show both the low 100s in New Brunswick and the high 14,000s in Quebec without minimizing or downplaying either extreme.
Beyond COVID-19, logarithmic scales are used to measure the magnitude of earthquakes and the intensity of sounds.
Updated on Thursday, April 9, 2020 at 7:20 PM CDT: Adds charts and text
April 15, 2020 at 5:30 PM: Updates chart sources
April 16, 2020 at 4:03 PM: Adds detail on logarithmic scales
April 21, 2020 at 2:21 AM: Updates image source
2:42 AM: Adds versioning to images
April 27, 2020 at 5:40 PM: Updates growth chart
May 12, 2020 at 12:40 AM: Adds chart