This includes time of day, day of the week, month of the year, season, anything useful.
I went here once around noon on a weekday recently and it was a 90 minute line, which is crazy-- no other attraction in Paris has had any line at all for me so far. Since the whole line is just standing outside in the open sun, and it was 95 degreees F, I had to just leave.
When do the crowds subside?