The baseband signal m(t) shown in the figure is phase-modulated to generate the PM signal φ(t) = cos (2πf_ct + k m(t)). The time t on the x-axis in the figure is in milliseconds. If the carrier frequency is
f_c = 50 kHz and k = 10π, then the ratio of the minimum instantaneous frequency (in kHz) to the maximum instantaneous frequency (in kHz) is _________ (rounded off to 2 decimal places).