The American Institute of Physics has published results of their national survey of high school physics teachers. Enrollment in high school physics classes has increased over the last 30 years, at twice the rate of increase of overall high school enrollment. Despite this, more and more high schools only offer physics in alternating years, and there has been little growth in the number of high school physics teachers.

 Read more at AIP.org: https://www.aip.org/statistics/reports/high-school-physics-overview-19