The Industry Analysis section of your plan discusses the industry in which you are operating. For example, if your nonprofit provides education to children, you should provide information on the education industry here. How big is the market? What segment of the market are you serving? Are there any industry trends that are changing the market? Document answers to these questions here.
In documenting your answers, be sure to cite the sources of your statistics. For example, the US Census can tell you how many youths live in the United States. There are many other organizations that conduct research you can cite in your plan.