Please explain the methodology - how was the data collected, and who was the sample population

https://www.cdc.gov/nchs/data/nhis/SHS_Tech_Notes-508.pdf

Please explain the topic and its importance.

Please explain the methodology — how was the data collected, and who was the sample population
Please explain “Note, this information can be found under the Methods section of this page” — Technical Notes for Summary Health Statistics Tables: National Health Interview SurveyLinks to an external site.Open this document with ReadSpeaker docReader — which is located at the bottom of the main data page under the “Notes” heading.]
in brief, what is this graphical representation showing,
explain the numerical findings in the data. What does your graph/figure show? Explain the results.
Explain the in-text citation or reference for the data/information at the end. Or please explain how to correctly do direct quotes

Please explain the methodology — how was the data collected, and who was the sample population