Here are some links to claim stats from insurers with the date that they were published. Click on the company name to access the claim stats:
AIG (2021) (interactive guide)
PDF Guide: AIG_Customer_Claims_2021
Legal & General (2021)
British Friendly (2020 stats).
Holloway Friendly (Claims performance in 2021).
The Exeter (2020 stats published in April 2021).
Vitality (Published 21st August 2021)
Aviva (Published May 2022)
Dentists Provident (2022).