Fig. 3

Spatial distribution pattern of CP in 2008, 2011, 2014, 2017 and 2021. Notes: ① Source: Authors’ own drawing, based on GeoDa 1.22.0.4 software. ② Source of the map of China: GeoAtlas (areas_v3). Map Review Number: GS Jing (2022) No. 1061. Obtained from https://datav.aliyun.com/portal/school/atlas/area_selector; ③ Undefined are Tibet, Hong Kong, Macau, Taiwan, and the Nansha Islands, which are not included in the study scope.