Date of my practical car test needed.??

Hi all, Can anyone advise me on how and where I could retreive confirmation on when I passed my practical driving test?. May seem a silly question but, As I was given 2 years to retrieve my actual license I therefore left it untill the last minute and now I am faced with insurance companys asking for the exact date in which I past and a license with the date I had received the license on. Although the time inbetween was only just over a year, I suspect that if I enter the actual date it may reduce my insurance. Any advis would be greatly apprieciated and will be awarded with 10 points he he.