Trend down Percentage of nursing workforce by class of nurse (RN, NP and RPN), based on CNO data. And pattern over time: all covered in one set of graphs. Percentage Shares of Nursing Employment Sources Citations “Cno Data Query Tool For Head Counts; Rnao Calculated Nursing Workforce Shares. ”. 2018. http://www.cno.org/en/what-is-cno/nursing-demographics/data-query-tool/.