use formats without release dates for calculations #24
Description
For some formats, release year is currently unknown. These are included in the market definitions, and this information can always be added; at the moment, they are completely excluded from the analysis: Before processing, these elements are removed. BUT they should be used for the total market:
We know when each file was created
We know what format it is
We know that the format belongs to the market
So we cannot calculate a curve FOR that format, but we can calculate the other curves considering it.