distribute	reads
0-500	0
500-800	0
800-1000	0
1000-1200	2
1200-1400	5
1400-1600	2
1600-1800	16
1800-2000	22
2000-2200	16
2200-2400	25
2400-2600	31
2600-2800	73
2800-3000	38
>3000	432
