Calculating the percentage increase or decrease is a bit trickier than working out the percentage of an amount but it's still easy when you know how.
Using what's the increase from 36 to 85 as an example
First you need to subtract the smaller number from the larger one. So in this case 85 minus 36.
Once you've done that you have to divide the result by the smaller number and multiply by 100 to get the percentage.