distribute	reads
0-500	94402
500-800	5065
800-1000	296
1000-1200	53
1200-1400	9
1400-1600	4
1600-1800	1
1800-2000	1
2000-2200	1
2200-2400	1
2400-2600	0
2600-2800	1
2800-3000	1
>3000	4
