Formula for total entries in a column and for percentage of certain value

Ok, this is going to be somewhat complicated to explain, but I will try my best.

I have a workbook that has 3 sheets in it, Arrests, SFST, and Stats

I need some help calculating the stats.

DUI Investigations needs to calculate a total number entries in column K of the SFST sheet, when a value of "yes" or "no" is entered
DUI Arrests needs reference column K of the SFST sheet, and return a value indicating the number of time "yes" appears in the column
DUI convictions will be the hard one, as it will need to check column G of the Arrest sheet for one of the following values "DUI 1st, DUI 2nd, DUI 3rd, DUI 4th" then cross-reference column I for a value of "conviction" and return the value for how many times the above option and "conviction" occur in the same row.

Then I can input the formulas for the last 2 stats by referencing the above cells.
% Arrests
% Convictions

If it would help, or make it possible, I guess I could split the "Arrest" sheet into "DUI Arrests" and "Other arrests" I have attached a sample workbook

I'm not sure how to remove the original sample workbook, but the 2nd one, "Arrests and SFSTs with content," has some rows of fictitious info