how did you calculate that number?
American citizens constitute about 4% of the world's population. The inverse of 4% is 25. Assuming your post #11 is correct that this nat gas find would supply the world about 8 months, I multiplied 8 by 25 to induce that this find would supply American citizens for 200 months. Divided by 12 it rounds to 17 years worth of supply if it were used for only American citizens.