distribute	reads
0-500	3593
500-800	2884
800-1000	1826
1000-1200	1809
1200-1400	1736
1400-1600	1740
1600-1800	1658
1800-2000	1618
2000-2200	1592
2200-2400	1507
2400-2600	1473
2600-2800	1473
2800-3000	1437
>3000	79120
