All amorphous panels suffer a drop the first year.  Yours seems like a big drop.  The good news is that they don't drop much after that.  But for long term durability, either monocrystaline or polycrystaline panels will far outperform amorphous for decades and decades.

The other thing to keep in mind is that rated output for ALL solar panels is under ideal conditions.  That means a totally cloudless hazeless sky, sun at solar noon, sun high in the sky, and very cold conditions.  As soon as the panel gets hot, output can drop 25% or more compared to rated.  Really, they generate panel ratings in the lab with artificial "perfect" conditions.  So you may never get rated output even from a monocrystaline panel.

Good luck and have fun!