Growth of different Fe II components in the quasar main sequence. The sample is divided into four subsets according to R_Edd: (1) R_Edd < 0.03 (71 objects), (2) 0.03 < R_Edd < 0.1 (325 objects), (3) 0.1 < R_Edd < 0.3 (471 objects), and (4) R_Edd > 0.3 (154 objects). For each subset, we found the mean ratio of different Fe II components in 4434–4684 Å range and broad Hβ (marked with different colours), as well as the mean of the FWHM Hβ. The mean values of each subset are indicated by the corresponding numbers (1–4) on the top and plotted over the quasar main sequence.