Fraction of QGs as a function of redshift in different overdensity bins. The blue circles and red squares represent the median quiescent fractions for galaxies in the lowest- and highest-density quarters, respectively. The error bars are the 1σ uncertainties of the medians derived via the bootstrapping method. We find that the fraction of QGs shows a clear dependence on the overdensity at z < 2. However, we do not find a variation of the quiescent fraction with the environment at higher redshift (z > 2).