distribute	reads
0-500	29239
500-800	41971
800-1000	16116
1000-1200	11406
1200-1400	8430
1400-1600	6350
1600-1800	4863
1800-2000	3870
2000-2200	3081
2200-2400	2460
2400-2600	2187
2600-2800	1744
2800-3000	1426
>3000	15479
