Missing entries in Calendar

[Marcel-Schubert]

There is a display problem in the calendar when some month has no activity. E.g. for me, there were no (tracked) activities in January and February, and thus the value for march appeared in column 1.

The underlying problem is that the table is filled by looping over monthly_distances, which might not have a entry for every month.
One solution would be to edit monthly_distances such that it does have an entry for every month (of all years that are present).
Alternatively, the table can be filled by a loop over values 1...12.

[Marcel-Schubert]

The current bugged version:

With 0 km entries:

With empty entries (the spacing looks very odd to me, but could maybe be improved by minimum or fixed column widths):