Conditional formatting

I’ve applied a conditional format to a row, so that if a specified cell has ‘Y’ entered, the whole row goes green. How do I apply this formatting to every row, without going through each row individually?

I’ve tried all the paste special suggestions etc, but the formatting gets applied so that (for example) if cell A1 has Y, every cell on the spreadsheet goes green. I want it so that if A1 has Y, row A goes green; if B1 has Y, row B goes green, and so on.