time series with bivariate data?

I have a datetime (yearly) variable which indicates when/if a subject registered, a count of the 400,000 subjects who registered at each facility and those subjects identified as being asked a particular question upon registration, a dichotomous yes/no. The requester asked that their time to registration at the facility and whether or not they were asked the question be presented. The hypothesis is that those facilities administering the question had more registrants. Would this be an appropriate approach for an analysis or is there something else I should consider? I've played around in SAS/Eg a while with this but the output isn't that interpretable. Thanks.