I expected the numbers to be even worse:
Job Polarization in the United States: A Widening Gap and Shrinking Middle, by Jaison R. Abel and Richard Deitz, Liberty Street Economics: ... A Hollowing Out of the Middle Not surprisingly, these patterns have shifted the distribution of jobs among these groups. The chart below indicates the share of workers in each of the wage groups in 1980 and in 2009. In 1980, three-quarters of all workers were employed in mid-skill occupations. Among the occupations included in this group, Machine Operators accounted for 10 percent of the U.S. workforce, and Administrative Support accounted for 18 percent. By 2009, the share of jobs in the mid-skill category had shrunk to two-thirds, with Machine Operators accounting for just 4 percent of all jobs and Administrative Support for 14 percent. Over this same period, there was an increase in the share of jobs in the high and low skill groups. High skill jobs increased their share from 12 percent to 15 percent, while low skill jobs grew from 13 percent to 17 percent. As a result, the share of jobs at the upper end and lower end of the distribution increased between 1980 and 2009, while the share of jobs in the middle group fell.
Clearly, the U.S. workforce has undergone a significant occupational restructuring since the 1980s. Along with an increase in the share of high skill jobs and low skill jobs, there has been a growing wage gap between workers in jobs that pay the most and those that pay the least. With a rising share of jobs at the upper and lower ends of the wage distribution and a wider gap in wages among occupations, jobs have become more polarized in the United States over the past three decades.
This looks like a supercritical pitchfork bifurcation (a potential path to chaos).