Own car insurance which SF class at the start?

Hello my own car is currently insured with my mother (she does not have her own car so my car is the only thing that is insured there) the insurance has the SF class 26 therefore the insurance is quite cheap. Now I want to clear the space so that my brother can insure his car there and first have cheap contributions. Therefore I want to open my own car insurance in my name. I own the driver’s license for 8 years and have since been absolutely accident free driving (can I prove that I have been with my mother’s insurance for 8 years). According to Google, you get into the SF class 1/2 ( 3 years in possession of the driver’s license) Is this the rule or do some insurers grant other discounts? I mean that some of my acquaintances didn’t start with SF0 and also got a better SF class and that as a beginner! Who knows themselves here or has their own experiences? Greetings