Mum & others - When investment returns (and interest rates) are high, insurance premiums go down. This doesn't indicate a fall in claims. It's so the insurers can pull in more premiums faster, investing them on rapidly-moving markets.
And the inverse. If premiums are high and/or claims harder to make, it might mean there's been an unexpected spike in claims. But insurers are in the business of risk assessment; it would have to be something extraordinary to have escaped their notice. Much more likely their finance is under-performing and they're trying to milk the policies.
Other things come into play, too, obviously, such as competition for market share and tweaking the rates for specialist insurance.
What I've been trying to do is break the perception of insurance as a communal piggy-bank. Hardly any business is a simple money in, money out equation. Where the business involves vast quantities of customers making regular payments to an organisation, it's a fair bet that organisation's main business is working the money markets.
I'm not saying it's a bad thing ... actually, I would if we look even further up the chain to the market-makers, but that isn't my point here! It's just the way things work under present-day capitalism. Jim & Jane faking domestic accidents has no material effect on your premiums.
Millions of 'em doing it, however, would - because the company has to keep enough money in its coffers to play with. Insurance would become a non-viable business. But a few dozen chancers? No. I wouldn't fake it - for one thing, it's criminal fraud. And if Jim & Jane do it too often, they'll find they can't get reasonably-priced insurance.
I have known a very few people whose strategy was to make sure the value of their claims, over time, equalled the premiums they'd paid. While they were committing fraud, I don't see them as terribly immoral. The insurers had the use of their money all that time, and had no doubt profited.