In 1980 an overwhelming number of 31 (!) players from the USA were in the top 50 of the WTA. Just 12 years later (1992) there were only 11 US Americans left. We have to consider this when we compare past eras. In 1980 US American players like Evert, Navratilova, teenagers Austin, Shriver and Jaeger and even grandma BJK were able to dominate the women's game because professional tennis hadn't really caught the world outside of the USA and maybe Australia and the UK. There were occasional stars in other countries (Bueno, and ... ?) but essentially it was an American affair with some Aussies plus Wade/Jones from Great Britain. In the late 80s and early 90s, though, WTA tennis had gone international, the fields were far stronger and audiences in non-english-speaking countries tuned in. Players like Graf, Sabatini, Seles, Hingis brought tennis to another level.