has a lower rate of observations beyond [*z*]{} of $\sim$0.5 because an IR spectrum is required with a different instrument in addition to the optical spectrum. This is not seen in the [@xshooter_survey] sample because X-shooter obtains optical and IR spectra in unison. However a gap is seen in the X-shooter metallicity sample (both the total sample and its high metallicity sub-sample) from 1.7 $<$ [*z*]{} $<$ 2.1 due to observational difficulties in obtaining all the lines needed for metallicity measurement (see text). As measuring the redshift does not require observing specific lines this gap is not seen in the [@xshooter_survey] redshift sample. We also compare these LGRB samples with our predicted LGRB rate estimate from @form_rate_letter (thick grey line) and find it to be in good agreement with the samples at [*z*]{} $<$ 2.5 and with the [@Perley_shoals_masses] SHOALS sample in particular at higher redshifts. KS test results for the lines in this figure are shown in [first@refLGRB\_num\_stat\_KS\_table,@]{} in the appendix. Note that the super solar metallicity LGRB sample follows the same distribution as the general LGRB sample, which suggests both that the metallicity of the LGRB hosts does not bias the likelihood of their metallicity being measured and 