Oh, sorry... And thanks for asking, I found a minor mistake from straight draw force calculations (I had wrong brace height... and brace height is really important parameter).
I suppose that brace height was 9 inch for the first bow and 7 inch for the second bow.
Then,
first bow: stored energy 76,6 J (straight draw force curve 66,6 J).
second bow: stored energy 98,0 J (straight draw force curve 85,4 J).
I calculated the stored energy with Excel and numerical integration using so called "Trapezoid rule".
So, these horn bows stores about 15 % more energy compared to straight draw force curve bow. And, basic, straight wooden bow stores about 5 % more energy compared to straight draw force curve. So, these horn bows stores about 10 % energy than straight wooden bow.
Summary:
-Straight, linear draw force (perfectly straight) stores 100 % of energy (we compare other bows to this, so that is why I use 100 %). We could also use for example value 0,5, because it stores half of the theoretical maximum of stored energy.
-These horn bows stores 115 % of energy compared to straight draw force curve.
-Straight wooden bows stores on average 105 % of energy compared to straight draw force curve.
Hopefully I am not too confusing...