China’s economy saw the weakest expansion in a year-and-a-half during the last quarter, official data show. Gross domestic product (GDP) grew 4 percent in the final quarter of 2021 from a year earlier, China’s National Bureau of Statistics announced on Jan. 17, down from the 4.9 percent gain in the third quarter—a further deceleration from the 7.9 percent growth in the second quarter and 18.3 percent expansion of the first. China reported a strong economy at the start of 2021 as activity recovered from a pandemic-induced slump the previous year. Yet the trend eased as the country suffered a few setbacks including an energy crunch, regulator curbs, declining property market, and sporadic COVID-19 outbreaks. GDP grew 8.1 percent throughout 2021, a better result than the above-6-percent growth target China set earlier last year. The revised growth of 2020 was 2.2 percent. On a quarter-on-quarter basis, GDP rose 1.6 percent from …