distribute	reads
0-500	55979
500-800	33401
800-1000	19216
1000-1200	17623
1200-1400	16193
1400-1600	15159
1600-1800	13900
1800-2000	12888
2000-2200	12282
2200-2400	11072
2400-2600	10440
2600-2800	9924
2800-3000	9328
>3000	168241
