Table 4. Cluster number determination from k-means testing.

k	Phenotypic	Genetic
2	44.8	36.7
3	61.5*	47.6
4	71.8	61.9*
5	76.0	69.3
6	83.4	79.2
7	85.2	83.3

Results for k-means testing of phenotypic and genetic correlation matrices using the average of the Lloyd (1982) and Hartigan and Wong (1979) algorithms. Hypothesized cluster number is the k-value input into the heuristic. Numbers reported for the phenotypic and genetic matrices are the average of the two algorithms’ results for the ratio of the between-groups sum-of-squares to the total sum-of-squares. The point at which the curve was determined to have its “elbow” is indicated with an asterisk.