According to the US Bureau of Labor Statistics, employment of registered nursing(which includes school nurses) is expected to grow 26% between 2010 and 2020.
(Innerbody.com)

Facts and Data

For employment of athletic trainers BLS reports a 30% increase between 2010-2020.
(education-reports.com)

-There are over 39,000 Certified Athletic Trainers in the United States.
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-There are about 45,000 school nurses employed in the United States today. (Alleducationschools.com)