Just a small but important point.
Those posts that told you to divide one specific gravity by another (i.e. 1.062 / 1.069, or 1.042 / 1.054) are wrong. You have to subtract the 1.000 before doing the division (i.e. .062 / .069 or .042 / .054). Even easier, multiply the numerator and denominator by 1000 (i.e. 62/69 or 42/54)
The previous posters %ages were correct because they had subtracted the 1 before doing the division. They just didn't say that in the explanation.