China's literacy rate has grown dramatically, from only 20% in 1949 and 65.5% in 1979. to 96% of the population over age 15 in 2018. In the same year, China (Beijing, Shanghai, Jiangsu, and Zhejiang) was ranked the highest in the world in the Programme for International Student Assessment ranking for all three categories of Mathematics, Science and Reading. China ranks first in the all-time medal count at the International Mathematical Olympiad with 168 goal medals since its first participation in 1985. China also ranks first in the all-time medal count at the International Physics Olympiad, the International Chemistry Olympiad, and the International Olympiad in Informatics.