They had a handful of deaths since they started in 1959. And their worst accident was a fatal aircraft failure, which is technically an aircraft accident, not a skydiving accident.
The numbers we have are averages, there are definitely people beating the average through greater attention to safety. And, unfortunately, some groups that are on the other side of average.
Equipment is getting better too, and I have no doubt is helping lower the death rates. Pretty sure that loads more people were dying under old rounds that today's controllable squares. Lots of people died in WWII in Jeeps under parachutes. I remember the museum in New Orleans saying that Jeep jumps had a fatality rate of something like 30%. Can't tell you how thankful I am that I've never been asked to do that.
Would be interesting (but small sample size) to do the math on the Golden Knights and find the mortality rate. I totally expect it to be lower than for the general skydiving populating.
Some drivers take more risks than others, and insurance companies gather a bit more data on that kind of stuff. Rates might be higher if you get a speeding ticket, precisely because that correlates with accidents and claims more than people who have no record.