Table 3. Distribution of 77–93 covariance pairs.

77–93 Pair	Observed	Expected	Preference	p-value
V-I	83	75.7	Favored
I-I	18	25.2	Disfavored
V-L	28	33.7	Disfavored	0.12
I-L	17	11.4	Favored
V-M	0	0.7	Disfavored
I-M	1	0.3	Favored

This is derived from the 147 sequences we used for covariance analysis.