distribute	reads
0-500	0
500-800	0
800-1000	0
1000-1200	1
1200-1400	4
1400-1600	12
1600-1800	16
1800-2000	19
2000-2200	13
2200-2400	12
2400-2600	2
2600-2800	4
2800-3000	2
>3000	0
