what's the average total cost of the hospital that involves a drug called epinephrine hcl this year?
select avg(t1.c1) from ( select sum(cost.cost) as c1 from cost where cost.hadm_id in ( select prescriptions.hadm_id from prescriptions where prescriptions.drug = 'epinephrine hcl' ) and datetime(cost.chargetime,'start of year') = datetime(current_time,'start of year','-0 year') group by cost.hadm_id ) as t1