If any country has its own income and savings to more then those savings to invest in economic infrastructure, the growth rate of the economy is higher than countries with low savings and investment.
If countries have pledged their revenue by saving more. Then the money was used for investment in infrastructure. It is the rate of economic growth than countries with low savings and investment.
If a country income ones bringing their savings. Then the savings to investment in economic infrastructure The growth rate of the economy will be higher than the country with saving and low investment.