Among the inspections done by sanitarian Joshua Rosa, how many of them have the result of "pass"?
have the result of "pass" refers to results = 'Pass'
SELECT COUNT(T2.inspection_id) FROM employee AS T1 INNER JOIN inspection AS T2 ON T1.employee_id = T2.employee_id WHERE T2.results = 'Pass' AND T1.first_name = 'Joshua' AND T1.last_name = 'Rosa'