Applying conditional formatting to multiple cells

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 is according 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 lines 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 line (C2). However, the resulting color formatting does match cell E16, as it should.

How does this work?

Thanks in advance for your help!