https://www.healthline.com/health/average-height-for-men#u.s.-height "According to the Centers for Disease Control and Prevention (CDC)the average age-adjusted height for American men 20 years old and up is 69.1 inches (175.4 centimeters). That’s about 5 feet 9 inches tall.
This number comes from data published in December 2018. The data was collected between 1999 and 2016 as part of a National Health and Nutrition Examination Survey.
The analytic sample included 47,233 men and women, all at least 20 years of age. Participants reported their ages, races, and whether they were of Hispanic origin. The average height of 5 feet 9 inches takes all groups into account."
There's a chart giving comparisons to other national averages ranging from 5' 4.25"(the Philipines) to 5' 11.9"(the Nethrlands). The
UK is 5' 9.9", Canada is 5' 10.1", which Mexico at 5' 6.5".
Remember that the term "Average Height" just gives you an area of about where people in that region are. In fact, adjustable seats exist because no one is actually "average", a fact that caused the deaths of many fighter pilots before they decided adjustable seats needed to be a thing.