c = 0
alignment feature   N   A   A +   A -
NS = 2  4487  0.824  0.829  0.819
NS = 3  5311  0.833  0.830  0.837
NS = 4  6388  0.828  0.830  0.827
NS = 5  7234  0.797  0.805  0.789
NS = 6  7500  0.832  0.835  0.829
50 ≤ sequence identity < 70  13187  0.799  0.799  0.799
70 ≤ sequence identity < 80  12152  0.827  0.832  0.823
80 ≤ sequence identity < 90  5550  0.865  0.871  0.859
90 ≤ sequence identity < 100  31  0.903  0.871  0.935
40 ≤ length ≤ 100  11191  0.768  0.773  0.763
101 ≤ length ≤ 200  14180  0.853  0.856  0.851
201 ≤ length ≤ 300  1697  0.637  0.641  0.634
301 ≤ length ≤ 400  3852  0.945  0.945  0.945
all alignments  30920  0.822  0.825  0.819