0 - 10 years. It is important to establish the number of years the client has held there licence. Within the first 10 years, insurers usually give a concession for every year held.
10 years plus - Insurers normally max out on concessions here.
If the customer has had a licence over 10 years. To save on time, simply confirm. "Have you had your licence for at least 10 years"? If yes then put down 10 years from today.