distribute	reads
0-500	54825
500-800	2385
800-1000	320
1000-1200	118
1200-1400	60
1400-1600	19
1600-1800	13
1800-2000	2
2000-2200	1
2200-2400	1
2400-2600	0
2600-2800	1
2800-3000	1
>3000	1
