[jjnoakes]

Those means different things.

Their wording means "we checked X sites and 77% of them met some criteria", which can be extrapolated to higher values of X (assuming the proper statistical care is taken, etc).

Your wording implies the same, but that's not good because you can't extrapolate to a larger X. You chose the sites after knowing they already met the criteria, and that changes the meaning.

[spurcell93]

I get the sense OP was being a bit snide

[bigiain]

The snide version would be "100% of 433,000". (Which is what I initially parsed it as, and nodded in agreement...)