distribute	reads
0-500	11803
500-800	22127
800-1000	9146
1000-1200	6638
1200-1400	5072
1400-1600	3763
1600-1800	3032
1800-2000	2428
2000-2200	2167
2200-2400	1762
2400-2600	1636
2600-2800	1334
2800-3000	1229
>3000	17999
