[feature] Show percents rather than absolute values in charts.

[pmrv]

Especially for the "Days of the Week" chart it helps a lot more to see relative data than absolute numbers, because doing X on 70 Tuesdays might be a lot if only 80 Tuesdays passed or might be the opposite if instead 300 Tuesdays passed.
So I'd like to see a toggle to switch between absolute and relative display in the charts. Would you be interested in adding something like this? If so, I would look into it and add PR a couple weeks down the road.

[lordi]

For the weekdays chart, I support the idea. There I would even prefer to show percentages without the ability to switch. For the other charts, it is quite unclear what percentage should mean (percentage of total ticks?, percentage of ticks in the visible time frame?, ...), so in order to avoid confusion I would keep the other charts as they are. What do you think?

I would appreciate a PR for percentage display in the weekdays chart.

[pmrv]

For, say the weekly display, I would have used 7 as a base, for months 31/30 and so on. So you always get the average number of ticks per day, but it's not as straightforward as for the weekdays, that's true and since the numbers are a lot smaller there anyway, it's not that important actually.

But I will look into the weekdays first and maybe we can take it from there.