Copying conditional formatting formulas

Hi all,

I've actualy already done what I needed to do, but as this is a very sensitive document I would like to know WHY it worked, just to be sure it will remain functional when used over and over...

I have a column of percentages and created three conditions in the conditional formatting rules to show if the percentage adheres to our standards:

If C2 is smaller than 72%, E2 will turn red =C2<72%
If C2 is between 73% and 91%, E2 will turn orange =AND(C2<91%,C2>73%)
If C2 is larger than 91%, E2 will turn green =C2>91%

I've copied this to all other rows below using the Format painter and it works perfectly on every cell.

How ever, if I select a cell lower down (for example E16) and look at the specific conditional formatting for that cell, the formulas remain the same. In the formulas, it still says they're based on the first row (C2). However, the resulting color formatting does match cell C16, as it should.

How and why does this work?

Thanks in advance for your help!