We present a sample of 38 intervening damped Lyman {alpha} (DLA) systems identified towards 100 z>3.5 quasars, observed during the XQ-100 survey. The XQ-100 DLA sample is combined with major DLA surveys in the literature. The final combined sample consists of 742 DLAs over a redshift range approximately 1.6<z_abs_=3{sigma}) from z~2 to z~5. In order to make a complete assessment of the redshift evolution of {Omega}HI, we combine our high-redshift DLA sample with absorption surveys at intermediate redshift and 21-cm emission line surveys of the local universe. Although {Omega}HI^DLA^, and hence its redshift evolution, remains uncertain in the intermediate-redshift regime (0.1<z_abs_=3{sigma}). Despite its statistical significance, the magnitude of the evolution is small: a linear regression fit between {Omega}HI and z yields a typical slope of ~0.17x10^-3^, corresponding to a factor of ~4 decrease in {Omega}HI between z=5 and z=0.

Cone search capability for table J/MNRAS/456/4488/table5 (Combined sample catalogue)