I translated Japanese news into English. WIll you correct the passage? Thanks in advance.

Property and casualty insurance companies have decided to raise voluntary automobile insurance premiums by the end of the next year. It is expected that the rising rate will be higher among elderly people, who are likely to have more accidents, will see the largest rises in their premiums. The annual increase for average customers is expected to be between 2,000 and 3,000 yen.
Automobile insurance is a main an important product, which accounts for about half of the total insurance profits. but However, it has been decreasing since for an number of reasons: a decrease in population, sluggish sales in of new cars (since young people don’t want to buy one), a decrease in owners of cars (due to the aging society) and an increase in the number of compact cars whose which have low insurance premiums is cheap. Also, an increase in accidents among elderly people has increased the burden of on insurance companies, deteriorating reducing their prospects of profit. This will lead to a wider range of rising rate of higher insurance premiums among for elderly people, which will be a rise of 20% among people at for those who are 60 or older over.
It is expected that fierce competition will start among insurance companies over the time and rate of premium rate increases and also over the acquisition of good contractors customers, who have less accidents. Contractors Customers need to be careful in when choosing an insurance company by comparing their service and products.

Well done! Your translation made good sense.

I translated Japanese news into English. WIll you correct the passage? Thanks in advance.

Property and casualty insurance companies have decided to raise voluntary automobile insurance premiums by the end of the next year. It is expected that the rising rate will be higher for elderly people, who are likely to have more accidents -  the annual amount of burden on the whole contractors  being among 2.000 yen to 3.000 yen.

(do you mean :

1. 'the annual burden on ALL THE CONTRACTORs' , OR

2. the annual burden on the whole)
Automobile insurance is the main product, which accounts for about half of the total insurance profits, but it has been decreasing due to a decrease in population, sluggish sales in new cars (since young people don’t want to buy one), decrease in owners of cars due to the aging society, and increase in number of compact cars whose insurance premium is cheap. Also, increase in accidents among elderly people has increased the burden of insurance companies, deteriorating (reducing/ worsening) their prospect of profit. This will lead to a wider range of rising rates of insurance premiums among elderly people, which . This will be 20 % among for people at 60 or olderabove.
It is expected that there will be fierce competition will start among insurance companies over the time and rate of premium rates and the acquisition of good contractors, who have less accidents. Contractors need to be careful in choosing an insurance company by comparing their service and products.