Where would I look to find statistics of hybrid class enrollment for the past three years?
You can find newer UHD enrollment data by using the Fact Sheet link: https://www.uhd.edu/administration/institutional-research/Pages/ir-sheet.aspx
This link will take you to University of Houston-Downtown Fact Sheets which present information on students and course enrollment. You should be able to locate the information on these sheets. Their are both preliminary and certified fact sheets. You will probably want to use the certified fact sheets.
You may also contact the UHD Office of Institutional Research, see Data Request Form on the right.