distribute	reads
0-500	29
500-800	5
800-1000	2
1000-1200	2
1200-1400	0
1400-1600	5
1600-1800	9
1800-2000	13
2000-2200	15
2200-2400	32
2400-2600	17
2600-2800	14
2800-3000	21
>3000	322
