what is the average weight gain in hatchling through 1 year?

I ask because I got my lesser boy and my pastel girl in November and they eat every 5 days (fuzzy rat) and have both shed once (complete shed) they are healthy and have good poos but havn't gained any weight. each time I weigh them they are about 200 grams give a take a few.

is this normal? My lesser boy took 2 fuzzies tonight so I am going to try 2 fuzzies every 5 days, is that ok? my pastel wouldn't eat the second one.
The size prey bigger then fuzzy is weaned and they are too big for these 200g babies I think.

does it sound like they need more food? larger food?