Doozie

The percentage would be12.79% for $300 billion to grow to to $1 trillion in 10 years.

Is that per year?

or over the 10 year period?

12.79% is yearly rate compounded every year for 10 years. Example:

$300 x 1.1279 =$338.37.........Year 1

$338.37 x 1.1279 =$381.65....Year 2

$381.65 x 1.1279 =$430.46....Year 3......and so on. If you continue like this, you should get $1 trillion in 10 years.