The U.S. Census Bureau conducts a variety of experiments to prepare for a full-scale decennial census and investigate possible improvements to operations. The Census Bureau is investigating possible strategies for sending mail to motivate recipients to self-respond. It is suspected that the choice of mailing strategy affects the distribution of call volumes to the Census Bureau's telephone helplines. For staffing purposes, more uniform call volumes throughout the week are desirable. In this work, we consider formal statistical methods to compare call volumes resulting from several recent experiments, and determine whether one mailing strategy yields a more uniform call distribution than others.