HI CHRIS - You are now throwing above average for your age. Your velocity will naturally increase with age i would say by sophomore year you should be around low 80's which is above average still. Try to get some professional pitching lessons and get your throwing motion as fluid as possible. Long toss - long toss more ! PLEASE STICK WITH YOUR FAST BALL AND CHANGE UP PITCH. Do not throw a curve ball till 16yr. Now you can practice a curve ball pitch when you have a catch, but not game SITUATIONS no matter what a coach tells you ! WATCH YOUR PITCH COUNT PER GAME AND TOTAL FOR THE WEEK. Play catch as much as you can - EVERY DAY ! Throw the ball hard when you have a catch. Teach you body to throw hard always. If you do not try to throw the ball hard your body will not learn to throw the ball hard - GOOD HARD THROWS FROM 60'. Stay away from heavy weights right know till you reach the age of 16yr even then you should work heavy lower body and light upper body. Do a lot of running when you can and short sprint work. Eat well take your vitamins and just Love the game you are off to a good start. BEST OF LUCK TO YOU - DO YOU THROWING TEN ROTATOR CUFF EXERCISE EVERY OTHER DAY IT WILL ALL PAY OFF!
http://www.asmi.org/SportsMed/throwing/thrower10.html GOOD LUCK TO YOU