I bought a VE 60th anniversary SV6 ute when i turned 18 and was insured with CGU, there premium was $2100 a yr (which at the time thought was a good price cause no one was gonna touch me for a V8 for anything under 5k). It came up for renewal so i shopped around and went with AAMI which dropped it down to around $1200. I then traded and bought a VE SSV sedan when i was 19 and swapped it over on the AAMI insurance policy and it went up to about $1600 a yr. i renewed again with AAMI on the SSV and 3 days later smashed her up good (20k worth) and had to make a claim ($1200 excess). Im glad i had just renewed so its locked in for a year, not looking forward to seeing what its going to be next time.
Oh, ive also lost my licence twice (Hooning and Driving without a licence) so im sure they would have calculated that in as well.
Hope this helps give you an idea..