Date: 2020-09-10 ~ 2020-09-16Date: 2020-04-23 ~ 2020-04-29Date: 2020-05-21 ~ 2020-05-27Date: 2020-06-18 ~ 2020-06-24Date: 2020-07-16 ~ 2020-07-22Date: 2020-08-13 ~ 2020-08-19Date: 2020-09-10 ~ 2020-09-160%20%40%60%80%100%PrevalenceMask Wearing Trend during COVID-19 Pandemic data from the Facebook COVID-19 Symptoms Survey