distribute	reads
0-500	0
500-800	102
800-1000	21
1000-1200	8
1200-1400	15
1400-1600	7
1600-1800	5
1800-2000	5
2000-2200	1
2200-2400	3
2400-2600	0
2600-2800	4
2800-3000	1
>3000	1
