Voter turnout in Harris County has dropped in the last 30 years, but presidential and midterm election turnouts still dwarf those during years in which no major national elections take place in November.

In 1988, a presidential election year, 64.57 percent of Harris County voters came out to vote that November, according to the Texas Secretary of State website. The number rose to 71.68 percent in 1992.

Since then, the number has steadily plummeted, despite a growing population. Only 58.37 percent of those registered to vote in Harris County participated in November 2016, a presidential election year.

Elections that are not in presidential and midterm election years draw few voters, according to the Harris County clerk’s office. For example, in November 2017, only about 7 percent of county voters cast a ballot.

However, when there is a major ballot issue, such as the propositions on the Harris County ballot in November 2015—which included $848 million in bond proposals—that number reached 20 percent, according to the county clerk’s office.