Relative deviation for two galaxies (Tol 1247-232 and Mrk 54) between measured dark counts and estimated dark current for random samples of 8 of 65 dark exposures obtained in two 3-month intervals, using the same aperture and wavelength range as the science data (880−912 Å in the coadded data, including detector offsets). The solid and dashed lines show the mean and the standard deviation of the 100 realizations, respectively.