Fender offers a list of serial numbers and dating information in the support section of its website, which shows that products made with S9 and five following numbers were produced in 1978 and 1979. This type of serial number came into use after the company was sold to the CBS company, which used the S series numbers into the early 1980s.
Prior to the company being sold, a standard number system running from 0 to 700,000 was used. There was also a set of serial numbers that had an L in front of the number in the early 1960s. This type of numbering system did overlap into the CBS ownership as well.