distribute	reads
0-500	8
500-800	9
800-1000	2
1000-1200	0
1200-1400	5
1400-1600	8
1600-1800	13
1800-2000	13
2000-2200	24
2200-2400	21
2400-2600	28
2600-2800	22
2800-3000	19
>3000	207
