Without attaching a specific frame of reference to the statement, it becomes an absolute comparison of (in this case) the afford-ability of gasoline now compared to the entire history of gasoline sales.

Look up the statistics on the "average" USian income in the 1990s. Comparatively speaking you'll find most people were not "doing very well." A larger percentage of the population may have been moved up in economic status/standing than in previous decades but that doesn't mean most people (meaning more than 50%) were doing "very well."

This suggests wages for most of the USAians were stagnat through the 1990s when adjusted for inflation.