@Subordinateclause
I've had a tiny amount of PM for 30 something years and literally never won a penny - I've definitely not had on average 1%! My daughter has only had hers a year and won something already.
The chance of winning each month is currently around 1 in 24000 and is going to drop to around 1 in 35000 soon.
That means that if you have 24000, on average you will win one prize each month, but in reality will win 0,1,2, 3 or possibly more prizes because that's how the statistics work out. The closer you are to the maximum £50k, the more likely you are to get close or even exceed the stated payout rate.
If you only have a couple of thousand, on average you will win one prize every 10 years and if you only have a few pounds worth, then statistically you're down to one prize in a lifetime, or possibly less.
But if you have millions of people all with a 'tiny amount' of PBs then most will win nothing, but a handful will win a decent sized prize.
I've currently got about £25k worth that's built up over the last couple of years and in 2019 I worked out my winnings equated to an interest rate of around 2%, which just beat instant access that year, and this year I've actually won a £1000 prize and 2 or 3 £25 prizes, so have done really well this year.
I think about 98% of prizes are for £25 and the others are more.
You can see details of the big prizes on the NS&I website. I like looking for those who've won loads from a £8 holding bought in 1976 or similar, there's always a few people like that so it does happen.
www.nsandi.com/prize-checker/winners