count the number of times that divalproex (extended release) has been prescribed to patient 70267 since 2105.
select count(*) from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 70267 ) and prescriptions.drug = 'divalproex (extended release)' and strftime('%y',prescriptions.startdate) >= '2105'