Fender Stratocaster made in usa z6168175 what is it?

I think I can narrow it down for you.
It seems you have an American made Strat, post 2000.
Here is a guideline that describes when the "Z" nomenclature began.
I hope this helps you & congrats on your Strat!

"With the year 2000 came the introduction of the "Z" prefix serial numbers on US made instruments, which stood for the 0 of the new millennium. A Z0 prefix dates to 2000, a Z1 prefix dates to 2001 etcetera. The American Deluxe Series instruments use the same dating convention but with the addition of a "D" in front of the "Z", i.e. DZ1, DZ2 etcetera. Once again, and as always, there is typically some overlap and carryover of number prefixes from year to year."