hits probability (poisson distribution)
0 0.6737947%
1 3.3689735%
2 8.4224337%
3 14.0373896%
4 17.5467370%
5 17.5467370%
6 14.6222808%
7 10.4444863%
8 6.5278039%
9 3.6265577%
10 1.8132789%
10 1.3695269%
4-6 49.7157548% 5+/-1
3-7 74.1976306% 5+/-2 (1sd norm. dist. =68%)
2-8 89.1478683% 5+/-3
1-9 96.1433996% 5+/-4 (2sd norm. dist. =95%)
0-10 98.6304731% 5+/-5