Spitzer variability fractions for L and T dwarfs (S. A. Metchev et al. 2015) and the Y dwarfs (this work). The points without error bars are the raw fractions (number of variable objects/total sample) while the points with error bars have been corrected for survey sensitivity limits. The error bars for the L and T dwarfs are 95% confidence limits while the error bars for the Y dwarfs are centered 95% credibility intervals. Note that the detection thresholds of this work and that of S. A. Metchev et al. (2015) are different.