Web usage mining, “WUM”, is an application of data mining techniques on web log data used to understand the who, what, why, and how of website users. Through this systematic review, we review the research of WUM techniques from 2014 - 2019 in order to understand the current state of WUM research and answer our research questions; (RQ1) what data sources are used in web usage mining, (RQ2) what data analysis methods are used to extract the knowledge, (RQ3) what are the applications of Web usage mining, and (RQ4) what future research can be done in the web usage mining area? Using a PRISMA approach to narrow the initial 778 search results, we completed a full analysis of 68 unique articles from four prominent IS databases. The article analysis showed WUM research is on the decline and revealed Personalization and Recommender Systems are the two most heavily researched WUM applications.