distribute	reads
0-500	7436
500-800	4809
800-1000	2959
1000-1200	3428
1200-1400	4251
1400-1600	5624
1600-1800	7529
1800-2000	9868
2000-2200	12250
2200-2400	15102
2400-2600	17982
2600-2800	21151
2800-3000	23850
>3000	348894
