for children of "Mexican-American" race/ethnicity*, ages 2 through 18.
The red lines show "percentiles". The thick red line in the middle is the 50th percentile, which indicates that 50% of the population of Boys has Height (or stature) taller than the line, and 50% are shorter. Similarly, the lowest red line, the 5th percentile line, indicates the Height where only 5% of the population of Boys is shorter.
Charts for adults male height and weight are available here. These are also interesting, because they not only show the average height, they also show that adults have a considerably higher prevalence of obesity than children.
The data source for this chart is the NHANES III survey, conducted in America during 1988 to 1994. The CDC used this dataset, as well as datasets from several older surveys, to construct the CDC standard pediatric growth charts.
* The "Race-Ethnicity" categories.
Created by Steven B. Halls, MD, FRCPC and John Hanson, MSc.