This emerging industrial economy quickly expanded to meet the new market demands. From 1869 to 1879, the U.S. economy grew at a rate of 6.8% for NNP (GDP minus capital depreciation) and 4.5% for NNP per capita. The economy repeated this period of growth in the 1880s, in which the wealth of the nation grew at an annual rate of 3.8%, while the GDP was also doubled. Economist Milton Friedman states that for the 1880s, "The highest decadal rate growth of real reproducible, tangible wealth per head from 1805 to 1950 for periods of about ten years was apparently reached in the eighties with approximately 3.8 percent."