In 1947 in the United States, nominal GDP was $237 billion and real GDP was $1,771 billion in 2005 dollars. In 2011, nominal GDP was $14,869 billion and real GDP was $13,228 billion (also in 2005 dollars). What were the annual average growth rates of nominal GDP and real GDP over 1947 to 2011? What was the average annual growth of the price level? Explain your answer for the price level.