Rate the safety of a company

I've been thinking of a way to get a good picture on how safe a company really is. The system I've come up with is using the FMCSA Safer program using their snapshot page at http://www.safersys.org/CompanySnapshot.aspxto to rate each company. However, you just can't take the OOS% or the accident numbers because the more trucks a company has of course the more accidents they will have. And some companies are not listed on this site. So this is what I have so far.

Take two companies you want to rate.
Take the greater number of units divide it by the lower number of units to get your multiplier number. For example one company has 10,000 units and the other has 500. The multiplier would be 20. Then you can take the numbers from the company with the lower units and multiply by 20 to make them equal. That should give you a better picture on the companies that run safer. OOS numbers would be harder because then you need to look at how many inspections has the company had. So I use the reportable accident number.

I'm just kicking this around right now and I would appreciate if anyone would like to help. Any ideas??

I believe a new driver should do all the research that he or she can do before talking with a recruiter or going to one company. In that research I would look for the following,

Steadiness of work
Level of pay and benefits
Company support on the road
Genuine respect from management
Amount of home time
How long do the drivers stay at that company
How well does the company take care of the equipment and how new is it
How well does the company reward safe driving and how much
Overall safety rating of the company

I know there's more for each type of driving but overall can anyone add more when looking for a company to work for?