Control the display unit length of `PlotRange`

Here I use the undocumented Charting`ScaledTicks function:

ListPlot[
 {{-20, 2}, {-10, 1}, {10, 0.001}, {20, 0.0000001}, {80, 0.000000001}},
 PlotRange -> {{-20, 80}, All},
 Ticks -> {
    Charting`ScaledTicks[{Identity, Identity}][-20, 80, {10, 2}], 
    Automatic}
]

What I know about this function I've mostly learned in the comments to this answer. In short:

Charting`ScaledTicks[{scalingFunction, inverseScalingFunction}][min, max, divisions]

where divisions can be a number, or {maximum number of major ticks, number of divisions between each pair of major ticks}, so the specification I used above asks for labeled major ticks every 10 units, with one minor tick in between each major one (i.e., two divisions between each major tick). Note that sometimes the behavior of divisions is quirky; I assume that it uses FindDivisions or similar behind the scenes, which always attempts to find "pretty" / "good" divisions according to a heuristic.