what was the first time patient 96774 was prescribed a medication using an sc route until 04/2102?
select prescriptions.startdate from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 96774 ) and prescriptions.route = 'sc' and strftime('%y-%m',prescriptions.startdate) <= '2102-04' order by prescriptions.startdate asc limit 1