distribute	reads
0-500	23828
500-800	13035
800-1000	6636
1000-1200	5854
1200-1400	5170
1400-1600	4358
1600-1800	3978
1800-2000	3541
2000-2200	3155
2200-2400	2826
2400-2600	2524
2600-2800	2254
2800-3000	2118
>3000	24123
