Using statistics from reputable sources can be a useful way to demonstrate the existence and extent of a problem and/or show changes in a situation over time. Articles or reports may provide useful statistics and ideally will tell you the source of the statistics they're citing, so you can better evaluate their credibility.
Statista (listed below) is a helpful database to start with. In addition to providing statistics and identifying the source, you can also download results in different formats: PDF, XLS, PNG, or PPT, which can be helpful for presentations.