Writing a JMP formula

Question

I have a data set from 1985-1996 showing yearly reductions in about 16 different cities. Not all of the cities have complete data sets. I have to find the mean of the yearly difference for each city. The data is listed by month but the numbers only actually change after the last month. There are holes all over the approximately 2000 lines of data. I would be fine if there were no holes, but I'm stumped. Can anyone steer me in the right direction?

michael_jmp · Answer

I'm not sure what you mean by "yearly difference for each city". Is that the range of values (max-min) for a given city in a given year? Or is it the difference between the average values for a city between two different years? Or something else?

If you could give a small example of what the data look like and what your desired result would be, it will be easier for someone to help you come up with a JSL formula.

Best,
Michael