They same get your quotes 21 days before renewal as this is meant to be the sweet spot for the best prices.
Factory worker is meant to be one of best job titles for a lower premium.
Always phone your existing insurance company and ask if that is the best price they can do on your renewal quote as sometimes they will match or better your comparison site quotes. As @gez said adding a second driver can bring the price down.
Have a read. Cheap Car Insurance
Always check on topcashback and quidco as you can get money off for using the comparison sites. You could also find the best deals and then go directly to there websites via TCB and see if its the same price while trying to get money back for using TCB. Hope that makes sense....does in my head