Mine was brought in in June 21, I believe he was .25 inch (Maybe smaller) when he was brought into the LFS. Now he’s just over an inch (maybe 1.25”) and 1 year old. Their growth rate is decent, around 1 inch a year. So, around 0.1” per month. Although their lifespan is supposedly short (Mines over that 1 year marker at this point). The average lifespan is only a year unfortunately, some may make it over that however I’ve not seen many that make it past that.
I will admit, I have a couple fish surpassing their lifespan with me though.