distribute	reads
0-500	765872
500-800	28876
800-1000	1777
1000-1200	220
1200-1400	37
1400-1600	8
1600-1800	2
1800-2000	0
2000-2200	1
2200-2400	0
2400-2600	1
2600-2800	0
2800-3000	1
>3000	8
