Best left to someone trained to do this.
Model 909 made from 95-96
100-350 or so
You can get an owner's manual for free at the S&W web site.
906 + 909 + 909 + 909 + 909 + 703 + 602 + 909 + 909 + 904 + 607 + 378 = 9,554
909/1
-909
0.001
136 + 909 = 1045
909/2 = 454.5
25% of 909 is 227.25
0.001
It is: 909/9 = 101