Crude Oil Source Identification of Asphalt via ATR-FTIR Approach Combined with Multivariate Statistical Analysis

Table 6

Result of principal component analysis.

Number of principal components	Eigenvalue	Variance contribution (%)	Cumulative variance contribution (%)
1	9.319	77.658	77.658
2	1.860	15.498	93.156
3	1.017	3.508	96.664
4	0.255	2.123	98.787
5	0.081	0.677	99.464
6	0.031	0.256	99.720
7	0.019	0.159	99.879
8	0.006	0.051	99.931
9	0.004	0.033	99.964
10	0.003	0.021	99.985
11	0.002	0.013	99.998
12	0.000	0.002	100.000