Authors’ contributions
Mengxin Xue conceived and designed the study, drafted the manuscript, designed the data collection tool and collected the data. Huiping Sun collected the data and edited the manuscript. Jin Xue organized the data collection. Jingxin Zhou, Junchao Qu, Siqi Ji and Yuan Bu did the data collection. Yongbing Liu conceptualized and designed the study, coordinated and supervised data collection, and revised the content of the manuscript. All authors acknowledge the final draft submitted and agree to be responsible for all aspects of the work.