Nesting a countif function

Thanks so much for viewing this and posting if you have any ideas.

I have a quarterly spreadsheet where I currently use a countif dividied by a countif to get percentages, COUNTIF(DP$8:DP$28,"=4")/COUNTIF(DP$8:DP$28,">0"), for about 500 different people, so I manually put in the ranges of like in the example 8 to 28, then 29 to 42, etc and you can see I wanted the response of 4 divided by all the responses. And since its survey responses, each quarter the ranges are different so I have to change them all each month and it takes forever. What I want to be able to do is dump the data into a spreadsheet and have a formula that just looks through the entire column, like DP8:DP20000, and there's a column next to it that determines the different people so using the function use that column to determine which records in the DP8:DP20000 to use. So can I use a countif and another function that looks at the person ID column so I don't have to put the ranges in. I've tried nesting if and using & and if just doesn't work, like COUNTIF(DP$8:DP$28,"=4" and D2(which has the person ID) = DQ8:DQ2000) or a different function if possible? Thanks so much. Kevin
DP DQ
Q10 Person ID
4 2132
3 2132
3 3637
3 3637
4 3637
3 3637