There are great basses being made every year.
The real question is what years did Fender make fewer lemons.
Any mass produced product with have QC issues.
1958-1972 were great years for basses. After 1973 it was hit or miss. I know peoples will say they have great basses from 1972-1977. From 1978-1981 fender was producing some of there worst stuff. So much so they introduced the Reissue AV Line in 1982. They first few years from 1982-1984. The Reissue AV's were great. These are the Fullerton models. They are highly collectible now.
1985-2007 Fender had good years, and bad years.
As for now, 2008 marked a big change for Fender. 2008-till the present. Fender has been on a roll. Some of the best stuff they have ever made.
Bottom line. Your best bet is to play one yourself before buying.