main ingredient

2013

2016

2019

Eigenvalues

Contribution rate/%

Eigenvalues

Contribution rate/%

Eigenvalues

Contribution rate/%

PC1

0.04177

88.12

0.025994

77.86

0.043087

80.47

PC2

0.003053

6.45

0.00457

13.69

0.007822

14.61

PC3

0.002123

4.47

0.002604

7.8

0.001695

3.17

PC4

0.000453

0.96

0.000218

0.65

0.000938

1.75