What is the average cost of health insurance?

Well, it doesn't much matter how much it costs; I am, and have been paying contributions for the "National Health Scheme" in the UK for forty odd years, and have used it once only. Seems to me I am in credit with them (as are probably most of the people) so with this in mind, why should we need insurance; isn't our contributions insurance enough. If not, then a refund is required, probably to donate to BUPA......