How do you calculate insurance premium for car?

Insurance premiums are probably not capable of being done by hand any more at least with most insurance companies. Rating systems have become so complex with so many factors involved, that calculation by hand is impossible. I remember a time when we did have to do this by hand when I first got into the insurance business. Now we rate 10 companies at one time in a matter of seconds and sour system lines the up from lowest to highest.