HONG KONG — China said Tuesday that its population declined last year for the first time in six decades, a historic shift with profound implications for the world's second-largest economy.Officials with the National Bureau of Statistics said mainland China had 1,411.75 billion people at the end of 2022, compared with 1,412.6 billion a year earlier, a decrease of 850,000. There were a total of 9.56 million births, a record low birth rate of 6.77 per thousand, and 10.41 million deaths. The announcement was part of a broader release of economic data for 2022, a year in which President Xi Jinping's…