distribute	reads
0-500	21782
500-800	21964
800-1000	10688
1000-1200	8395
1200-1400	6783
1400-1600	5466
1600-1800	4534
1800-2000	3749
2000-2200	3057
2200-2400	2574
2400-2600	2126
2600-2800	1800
2800-3000	1566
>3000	10555
