Time evolution of the H-band break ratio. Different symbols represent measurements of different supernovae, as noted in the plot. Blue, black, and red symbols represent SNe Ia with optical light-curve decline rates in the range Δm₁₅(B) < 1.0, 1.0 < Δm₁₅(B) < 1.6, Δm₁₅(B) > 1.6, respectively. The inset illustrates the definition of the H-band break ratio with the spectrum of SN 2011fe at 12 days past maximum. The linear fits to the post-peak decline are plotted as solid lines when more than two data points are available and as dashed lines when only a single data point is available and the error-weighted mean decline rate is assumed. There is a wide range of peak H-band break ratios, but the post-peak declines are remarkably uniform.