After looking at all of your pics its no surprise he jumped out 5 Oscar's and a aro? Thats tank is way over stocked
so you went from 4 or 5 inches to 19 inches in 9 months? Thats either 1.55 or 1.67 inches a month depending on the starting point you want to use. its about half the growth rate of what you said is normal...In my experience aros and Oscars are not good match this is my experience I have three aros and not one of them jumps I have a 19 inch aro right now that I got at about 4 to 5 inche on may 25 2014 so less then a year. my aros do not jump and hit the lid I can touch my big one and he wont budge. Do they jump in the wild yes for food I feed them massivore pellets witch sink and they go right to the bottom to get them. Also allot of fish can grow 3 inches a month gars arapiamas aros and even some plecos I know this to be a fact becuz I have everyone of those fish I just mentioned and if fed everyday to there hearts content they can grow very quickly tank size playes a huge role in growth. My aros in my 450g gallon tank and will grow so much faster then somebody with a 100g or even a 200g u cant convince me other wise I have living proof.