distribute	reads
0-500	4105
500-800	2950
800-1000	2818
1000-1200	4148
1200-1400	6450
1400-1600	9950
1600-1800	14761
1800-2000	19848
2000-2200	23499
2200-2400	25411
2400-2600	23795
2600-2800	20122
2800-3000	16559
>3000	43844
