For the second part of your question, you could do a countif formual. Lets say you have a table like this:

A1 True
A2 True
A3 True
A4 False
A5 True

If you created a countif formula in cell A6 to count the True's, =countif(a1:a5,True) and then another countif formula in A7 to count the False's, =countif(a1:a5,False)

Then divide the two and click your % button. You can enlarge the range of the cells if you have a large report for example =countif(a1:a1500,True)