Evolution of the dark matter fraction and related parameters for two lens samples: COSMOS (crosses) and JK07 (stars). Top left panels: evolution of the DM fraction in the Einstein radius with the redshift. The least-deviation fits are displayed (solid lines), and follow the relations f_DM(<R_E) = −0.18 × z + 1.00 for COSMOS and f_DM(<R_E) = −0.18 × z + 0.38 for JK07. Top right panels: variation of the DM fraction as function of the ratio of the Einstein radius versus effective radius. The least-deviation fits give the following relations: (COSMOS) and (JK07). Bottom panels: evolution with redshift of the Einstein radius versus effective radius. The least-deviation fits give the following relations: (COSMOS) and (JK07). For JK07, we report the results obtained for galaxy models without adiabatic compression. The slopes are similar for models with adiabatic compression.