how much labetalol was last prescribed to patient 99205 in 12/2102 dosage?
select prescriptions.dose_val_rx from prescriptions where prescriptions.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 99205 ) and prescriptions.drug = 'labetalol' and strftime('%y-%m',prescriptions.startdate) = '2102-12' order by prescriptions.startdate desc limit 1