This paper is from the China Centers for Disease Control and Prevention Weekly journal. I am posting it here because the website often fails to load. I am not involved in the study, and there is no need to credit/mention me.
Original link: http://weekly.chinacdc.cn/fileCCDCW/journal/article/ccdcw/newcreate/COVID-19.pdf
Citation: The Novel Coronavirus Pneumonia Emergency Response Epidemiology Team. The Epidemiological Characteristics of an Outbreak of 2019 Novel Coronavirus Diseases (COVID-19) - China, 2020. (2020). China CDC Weekly, 2. http://weekly.chinacdc.cn/fileCCDCW/journal/article/ccdcw/newcreate/COVID-19.pdf