distribute	reads
0-500	279321
500-800	9121
800-1000	543
1000-1200	126
1200-1400	32
1400-1600	9
1600-1800	3
1800-2000	1
2000-2200	1
2200-2400	0
2400-2600	0
2600-2800	0
2800-3000	0
>3000	0
