Evolution of the galaxy number density as a function of redshift for the mass limits log (M/M_⊙) > 9.0, log (M/M_⊙) > 9.5, log (M/M_⊙) > 10.0, log (M/M_⊙) > 10.5 and log (M/M_⊙) > 11.0. For each mass limit, the solid line gives the mean number density across the four fields, whilst the shaded region gives the scatter between the fields. Dashed lines give the measurements that are incomplete based on our mass-completeness estimates. Below z ~ 1, the numbers of massive galaxies remain relatively constant, whilst the numbers of low-mass galaxies increase with decreasing redshift. Above z ~ 1, the build-up of massive galaxies is seen with a significant increase in galaxies of masses log (M/M_⊙) > 10.5 and log (M/M_⊙) > 11.0 evident from z ~ 2 to z ~ 1.