It shows: The decades of the 20th century
This is what you see: What I drew was the closest I could come. It is very hard to describe. The ones that are in color are the only ones I see in color.
This is what I could not show better and what is missing: I tried to show the incline upwards, but it is actually much steeper than that. 2000, 2001, and 2002 are like steps but i couldn't really draw that.