distribute	reads
0-500	14
500-800	14
800-1000	14
1000-1200	27
1200-1400	31
1400-1600	29
1600-1800	29
1800-2000	13
2000-2200	5
2200-2400	1
2400-2600	4
2600-2800	1
2800-3000	0
>3000	0
