WE use CNA as well and those were the numbers. The liability and umbrella pkgs were not as bad as I expected. So they stick it to you on something not too easy to get and not too negotiable. I think they are looking at the over all picture. Mu agent told me the market was tight (hard market) and will remain so for a few years. Then it will get more competitive. I'm probably paying in the mid to high teens for my trucks and none are super heavy duty ones.
I don't like the numbers but I find for me that other companies promise stuff they can't deliver. Apply pesicides, drop ya, plow snow, drop ya, work on athletic fields , drop ya after having sucked you in with we can save you money. Or, they will put it to you in the second year. They also will play with payroll numbers for rating and premium purposes with out your permission to get the pakg sold. Then next year you get an audit and surprise, suprise you under paid and you owe money. With CNA the contractor is KING.