md`This map differs dramatically from the previous one! The decline in mortality in the Black Belt is much more pronounced, as is an increase in the Midwest, such as the ${tex`+254.9\%`} ${html`

`} increase in Randolph County, Indiana. But is this a good way to look at this data? Consider Plymouth County again: it increased from ${tex`0.9`} to ${tex`3.2`} deaths per 100,000, which is ${tex`\tfrac{3.2 - 0.9}{0.9} = +243.8\%`} ${html`

`}. Meanwhile, Apache County “only” increased by ${tex`\tfrac{31.5 - 18.6}{18.6} = +69.7\%`} ${html`

`}. Is the change ${tex`3.5\times`} more notable in Plymouth County than in Apache County? Probably not: counties with a low initial mortality rate—the denominator in our relative change formula—have a much larger relative change for the same absolute change. On the other hand, a tripling of the alcohol-related mortality rate could be a significant concern. Also, note that the color scale above is not symmetric: its minimum is ${tex`-83\%`} ${html`

`} while its maximum is ${tex`+265\%`} ${html`

`}. In other words, the scale treats ${tex`+50\%`} ${html`

`} as significant as ${tex`-16\%`} ${html`

`}, and ${tex`-50\%`} ${html`

`} as significant as ${tex`+160\%`} ${html`

`}. If we force the scale to be symmetric, we see another dramatic change.`

Purpose-built for displays of data