Population size in million in 2022/1990, current nominal GDP in trillion in 2022, as well as expected future annual instantaneous growth rates of population and GDP, respectively, are listed for four big countries and GBA as below. China Pop. size 1,412/1148 Pop growth (%) 0.1 GDP 18.32 GDP growth (%) 5.2 India 1,417/838 0.8 3.47 U.S.A 339 / 250 0.5 25.04 1.5 Japan 124/124 -0.4 5.00 GBA, China 86.2 1.0 2.08 6.7 0.5 6.5 Using continuous model to calculate follows. (1) the population growth of the four countries between 1990 & 2022 and put each into zero/ slow / median / high category of population growth. (2) In which year will China (Yc) and India (Yi) become the largest economy, respectively? What is the difference in GDP per capita between the US and China in the year of Yc? (3) In which year will India and GBA overtake Japan in economy, respectively? (4) Based on the results above, briefly discuss the increasingly intensified competition among four big economies and the regional cooperation in GBA (