Ooops! Sent message too soon.
I couldn't find a breakdown by area for the whole country, but this is a graph for my area. Yes, it's just averages, but it represents the sum of individual cases.
In 2017, I had a heart attack and was taken to ambulance and had a stent fitted within an hour of the heart attack. The ambulance arrived within minutes. Timing was critical and, as a result of the speed, I don't have any damage to my left ventricle, which delays would have caused.
Heart attacks are Category 2 calls, so these days I would have had to have waited an average of 50-80 minutes (it's improved over the summer months). Even if I'd "only" waited the average of 50 minutes, it would have been too late. I could have died or, at best, been left with permanent damage to my heart. Unfortunately, half of people have to wait more than the average time.
Apparently, the South Western Ambulance Service NHS Foundation Trust has the worst ambulance waiting times in England (sorry, don't know about Wales).