Here is a flashback to mid September, 2014 when I recorded my strongest sprint session. My power output was 66 W average over 20 minutes. Two of my four sprints were at about 80 W average power, and the work output was 290 met minutes.
By comparison, one of my worst sprint sessions recently was in mid February 2016, when my power output was only 22 W average over 20 minutes. My first sprint was at 55 W average power, but it fell to less than half of that subsequently. The work output was only 100 Met minutes.
Moral of the story? Don’t get discouraged when you have a slump. Though I haven’t yet surpassed my original record, I have recovered significantly from this past winter’s slump, and now average about 45 W in a 20 minute sprint session.