Mandarin is the official language of China, but it’s far from spoken by everyone in the country.

As of the end of last year, about 70 percent of Chinese citizens (over 900 million) were able to speak Mandarin, according to the Ministry of Education. The figure was hailed as an improvement from the end of the last century when only 53 percent was fluent in the language, also called “Putonghua” or “the common tongue”.

The ministry said it hoped to achieve “basic” national coverage of the language by 2020 as China continues to urbanize and remote regions with ethnic populations become stronger in Mandarin.

China has been promoting Mandarin as the country’s official language for decades. However, some officials have said the country is too large and lacks too many resources to ensure Mandarin is learned by all its people.

This past year, Xinjiang went on a hiring spree to fill its schools with Mandarin-speaking teachers while regular Xinjiang teachers have been reassigned to undergo an “anti-separtism” curriculum.

Although Mandarin is taught throughout the world in China’s Confucius Institutes, some places are challenging the dominance of China’s official language with courses in Cantonese, the language of Hong Kong and southern China.