Updated the code to assign province‘s name to a city based on the year
Added more data like Yunnan and Guizhou
Extended the year range to 2022
Fixed some data errors
Vectorized the merging functions
Corrected the region codes of Xinjiang
Updated the code to assign province‘s name to a city based on the year
Added more data like Yunnan and Guizhou
Extended the year range to 2022
Fixed some data errors
Vectorized the merging functions
Corrected the region codes of Xinjiang