world first motor car Micron quarterly revenue and net income historical data In 1934, professor rei, of the center for fluid mechanics, used model cars to measure the aerodynamic drag of various bodies in wind tunnels Interest rate, in the form of expression, refers to the ratio of the amount of interest to the total amount of borrowed capital in a certain period of time.  the interest rate is the interest level per unit time of the unit currency, indicating the interest rate. Economists have been looking for a theory that can fully explain the structure and change of interest rates. Interest rates are usually controlled by the central bank of the country and administered by the federal reserve board in the United States. Today, interest rates are one of the important tools for macroeconomic regulation. In the early 20th century, famous American economist elvin fisher developed the theory of economic gain. In its book "the nature of capital and yield", first, the concept of yield is analyzed in terms of the performance of earnings, and three different types of benefits are proposed: (1) the equity of enterprises in general (including the transfer of shares, or shares, buy and sell, should according to the state administration of taxation on several tax equity investment business issues notice "(guoshuifa (2000) no. 118) the relevant provisions. Where the equity transferor should share the accumulated undistributed profit or accumulated surplus accumulation fund of the investor, the income derived from the transfer of equity shall not be recognized as the income derived from the nature of the dividend. In 2010, China overtakes Japan for being the other world's economy. According to economists, China continues to be a developing country with fast pace of growth. Data released that Japan\'s gross domestic product is $1.286 trillion while it is worth $1.335 trillion for China. Another source shows that Japan is increasing at 2 to 3 percent in in comparison with 10 percent 12 months of China.