distribute	reads
0-500	32172
500-800	44617
800-1000	21565
1000-1200	15578
1200-1400	10866
1400-1600	7560
1600-1800	5259
1800-2000	3452
2000-2200	2270
2200-2400	1525
2400-2600	946
2600-2800	635
2800-3000	394
>3000	729
