Above is a video showing the amounts of professional workers living in Corona through various time periods. As the video indicates, the percentage of professional workers over the total population increased from 2.9% in the 1940 to 17.0% in 2000, before decreasing to 10.7% by 2006.
Clerical/sales/kindred workers have always been a staple in the economy of Corona. Since 1940, the percentage of clerical/sales/kindred workers has fluctuated from anywhere between 17.5% in 1960, to 10.8% by 2009.
The percentage of service workers in Corona has remained consistently low, reaching a 70 year high in 2000 with 7.2%.
According to the Census data, the unemployment rate in Corona was highest in 1940 at 5.5% and lowest in 1960 at 1.7%. However, it is important to note that since these statistics are taken from the Census Bureau, it likely does not include illegal aliens who live in the area.
pretty =)