19 Year old new driver cheapest insurance £2000 for 1.0 toyota yaris with a black box

Recently i passed my driving test (26/07/17) and started to look for car insurance. I checked a lot of cars and the insurance quote wont go down no matter what i do. I added my parents to it, tried all the trix and it just wont go down from 2000 with a black box.How ever car with 1.6 or 1.8 engines are only £200-£300 more a year.any ideas why its so expensive? Is it because i just passed, if so wen will the price go down?