Table 1  Number of reference alignments and average Structure Conservation Index (SCI) for each alignment of k sequences.
k2  k3  k5  k7  k10  k15  total
no. aln.  8976 (118)  4835  2405 (481)  1426  845  504  18990
∅ SCI  0.95 (1.05)  0.92  0.91 (0.87)  0.90  0.89  0.89  0.93
Values for the previously used data-set1 [22] are given in brackets.