WT: r = -0.44, p = 0.201; slope = -0.82 per week (95% CI -2.19 to 0.54), slope p = 0.201, R^2 = 0.20
KO: r = -0.86, p = 0.001; slope = -0.97 per week (95% CI -1.45 to -0.50), slope p = 0.001, R^2 = 0.74
Difference in slopes (KO - WT) = -0.15 per week (95% CI -1.46 to 1.16), t = -0.24, df = 16, p = 0.811
Common slope = -0.90 per week (95% CI -1.53 to -0.27)
WT residual SD = 9.24
KO residual SD = 3.35
Robust (HC3) test of the difference in slopes: p = 0.824