Most listings are in the $10's per square foot per year. The Corona submarket is seeing a decline in rates. In the last 3 months, the median rate fell $6 per sqft per year. That's a 23% decrease in rent.
Compared to the rest of the Metropolitan Los Angeles market, the Corona region has lower rates, so you should have no trouble finding a great deal in this depreciated region.
In the last 90 days, 29 listings have been listed, which means spaces are probably going fast. You'll want to be prepared to tour spaces as quick as possible. There aren't many listings below 2,000 square feet on the market, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,560 sqft. Most buildings in this market are approximately 2 stories. Most buildings in this market were built in 2005 and are Class B.