Each of the 20 components of the PCA decomposition shown in each panel (red dashed line for BAL dataset; blue solid line for non-BAL dataset). Each component represents an eigenvector of the 20 component PCA. The first plot on the top depicts the mean spectrum of the total dataset. This mean spectrum is coincident with the Vanden Berk et al. (2001) composite spectrum which reinforces the generalized nature of our selected data sample.