distribute	reads
0-500	0
500-800	39
800-1000	7
1000-1200	1
1200-1400	2
1400-1600	0
1600-1800	0
1800-2000	1
2000-2200	1
2200-2400	1
2400-2600	1
2600-2800	1
2800-3000	1
>3000	8
