distribute	reads
0-500	0
500-800	160
800-1000	36
1000-1200	19
1200-1400	15
1400-1600	4
1600-1800	8
1800-2000	8
2000-2200	3
2200-2400	4
2400-2600	1
2600-2800	2
2800-3000	1
>3000	11
