need help reading nozzle chart?

can some please show me how to read this nozzle chart! Thanks it looks simple.

Find the pressure you are at or want to be at on the top first, then follow that row down to the Gallons per Minute (GPM) you run. follow that row left to the nozzle size. If you have questions give me a call or send me your email and I'll send you over a little nicer chart

It's a lot easier using a calculator.
http://www.pressureparts.com/nozzlecalculator.aspx/

Andy heres my email: qualpressurewash@yahoo.com

Thanks ralph! good info