For the sanitarian who lives on 5000 N Wolcott Ave, how many establishments did he/she inspect in the May of 2011?
sanitarian refers to title = 'Sanitarian'; 5000 N Wolcott Ave refers to address = '5000 N Wolcott Ave'; in May 2011 refers to inspection_date between '2011-04-30' and '2011-06-01'
SELECT COUNT(T1.inspection_id) FROM inspection AS T1 INNER JOIN employee AS T2 ON T1.employee_id = T2.employee_id WHERE T2.address = '5000 N Wolcott Ave' AND T2.title = 'Sanitarian' AND strftime('%Y-%m', T1.inspection_date) = '2011-05'