advice for rushing frats

Just wondering if someone in a frat could provide some information on how much of the following years pledge class comes from the dirty rush process. My friends and I haven’t been invited to any houses this term (we know people go to the houses for dirty rush events), but we want to still rush in the fall and would like to know how much harder it will be without being dirty rushed in the spring. Any advice is appreciated, but would love to hear from actual fraternity brothers!