Panel a): growth rate in number density after accounting for star formation evolution. Different thick lines and filled colour points represent estimates at different redshifts (dotted, dashed and solid for z ~ 0.35,0.55, and 0.75, respectively). For comparison, thin lines and empty points are the major merger rate estimates by de Ravel et al. (2010). Panel b): merger per Gyr per galaxy as a function of mass. Same lines and points as in panel a). Predictions based on cosmological simulations from Stewart et al. (2009), for mergers with mass ratio m/ℳ > 0.1, are plotted as thin lines and black cross for the lowest and highest redshift bin. Panel c): merger per Gyr per galaxy as a function of redshift. Thick lines and points represent various mass ranges (dotted, dashed and solid for log (ℳ/ℳ_⊙)  ~ 10.55,10.85,11.15, respectively). Predictions from Stewart et al. (2009) for m/ℳ > 0.1 are plotted as thin lines and black cross for log (ℳ/ℳ_⊙)  ~ 10.3 (dotted line) and log (ℳ/ℳ_⊙)  >  11 (solid line).