wicked:
10" to 20" and 4 lbs this year is pretty fast growth. If you're only feeding 2 lbs or so a day, you must not have a lot of CC stocked (or at least eating the feed every day).
That is indeed one fat (female) CC. I cleaned a couple 22 inchers this week that weighed 4 lbs 1 oz and 4 lbs 3 oz - your floater was a porker!