Table 3. PLS‐DA parameters and permutation test for distinguishing between age groups.

		PLS‐DA parameters
Age (yr)	Group Numbers	Componentsa	Q2	R2	Q2/R2	Ppermutationb
0.5–1	21–23	1	0.682	0.756	0.90	0.01
1–2	23–20	2	0.119	0.750	0.16	0.04
2–3	20–18	3	0.086	0.803	0.11	0.24
3–4	18–23	1	-0.243	0.448	-0.54	0.41

PLS-DA, partial least squares-discriminant analysis; yr, year; Q², predictive capability; R², correlation coefficients.

^aThe number of components based on Q² indicates the best classifier of PLS-DA using a 10-fold cross-validation method.

^b100 random permutations were performed.