distribute	reads
0-500	0
500-800	161
800-1000	39
1000-1200	13
1200-1400	12
1400-1600	12
1600-1800	5
1800-2000	4
2000-2200	4
2200-2400	1
2400-2600	3
2600-2800	2
2800-3000	1
>3000	23
