distribute	reads
0-500	90542
500-800	8052
800-1000	710
1000-1200	168
1200-1400	42
1400-1600	16
1600-1800	3
1800-2000	0
2000-2200	0
2200-2400	1
2400-2600	0
2600-2800	0
2800-3000	0
>3000	0
