Table 2. Covarying ISM positions and their most abundant nucleotide configurations.

Covarying group	NT configurations	Coverage	Representative position
241, 3037, 14408, 23403	TTTG, CCCA	96.19%	23403
2480, 2558	AC, GT	98.68%	2558
8782, 28144	CT, TC	98.52%	8782
17747, 17858, 18060	CAC, TGT	98.38%	18060
28881, 28882, 28883	GGG, AAC	98.94%	28881

The first column shows the group of covarying positions; The second column shows most abundant nucleotide configurations at those positions; The third column shows the number of sequences associated with the nucleotide configurations listed in the second column and the fourth column is the representative positions we picked to represent all the positions in this group. From this table, we can see that we can reduce the ISM size by 45% at a small cost to resolution.