Percentage of total for each generation. Your assumption of this info is that we should add them together. But if you look at the opposite numbers (percentage of those not identifying as LGBT+) you get 97% + 96% + 93% + 84% + 72% giving us a grand total of 442%.
Obviously you can’t have more than 100% of anything but it does illustrate that addition is not the method we should be using.
Instead we average them. Giving us 11.6% of the total population identifying as LGBT+.
The real information we’re seeing is that the amount of those who identify as LGBT+ increase with every generation.