Most listings are in the $20's per square foot per year. The Kent submarket is going through a a rise in rates. In the last 3 months, the median rate rose $1 per sqft per year. That's a 5% rise in rent.
In the last 90 days, 1 listings have been posted online, which means spaces are probably going fast. You'll want to be prepared to make an offer immediately. There aren't many listings below 2,000 square feet available, so finding a space for a small business might be tough.
The standard measurement for office space in this area is around 1,950 sqft. Most buildings in this market were built in 2013 and are Class A.