repeating or find or ?

I currently have a popup list and a go button... A user selects a city out of the list and hits the go button and the fields to the right are populated. (i.e. percentage of males, females, percentage of age ranges, etc.) The database already has a gender field and an age field which is populated with "M" or "F" and the actual age repsectively. I simply created a calc field that states "if Gender="M", 1,""). I then do a summaryfield that counts the number of "M", then I do a calc field that shows summaryfield/total_city_pop. This gives me the percentage of Males as a total of a certain city population

this works, but is obviously a longhand and screwed-up approach. Everytime the user clicks on a new city, the database recalcs all of the summary fields. I need to have a script that is run once and stores the data into fields for quick access for the next time a user clicks on the same city, so it doesn't recalculate all of the time..I think... or simply a betterr calc field...I don't know?

thanks