distribute	reads
0-500	4356
500-800	2858
800-1000	2151
1000-1200	2603
1200-1400	3352
1400-1600	5114
1600-1800	7787
1800-2000	11306
2000-2200	15614
2200-2400	19602
2400-2600	22899
2600-2800	24893
2800-3000	25652
>3000	197821
