"How does 25% go to 15% turn into a 75% difference?"
My percentage was off a bit since I just did it in my head. But, 25% is about 67% higher than 15%. If you don't believe me, multiply .15 x 1.67. The answer is .25. Just simple math. The number of deaths worldwide from covid is about 5 million. The number of deaths in the US from covid is about 758 thousand. That is about 15% of the total, NOT 25%. 25% would be 1.25 million.