distribute	reads
0-500	0
500-800	0
800-1000	0
1000-1200	2
1200-1400	2
1400-1600	3
1600-1800	7
1800-2000	14
2000-2200	24
2200-2400	67
2400-2600	89
2600-2800	151
2800-3000	218
>3000	3211
