The best source for this is the Common Data Set (http://oregonstate.edu/admin/aa/ir/common-data-set) created by the OSU Institutional Research Office. You can access these datasets here. Within the dataset navigate to Section I: Instructional Faculty and Class Size. The total number of instructional faculty should be on the table on the bottom of the page.

The question is asking for full-time instruction faculty not instructional staff.

Question 25. Instructional Faculty. Instructional faculty are defined by the U.S. Dept. of Education as: 

members of the instruction/research staff who are employed full-time as defined by the institution, including faculty with released time for research and faculty on sabbatical leave. 

Full-time counts generally exclude faculty who are employed to teach fewer than two semesters, three quarters, two trimesters, or two four-month sessions; replacements for faculty on sabbatical leave or leave without pay; faculty for preclinical and clinical medicine; faculty who are donating their services; faculty who are members of military organizations and paid on a different pay scale from civilian employees; academic officers, whose primary duties are administrative; and graduate students who assist in the instruction of courses. Pl ease be sure the number reported, and the basis for counting, are consistent with those for 2010-11 (unless in previous years faculty were counted who should have been excluded according to the above definition). Please footnote any discrepancies.