what is the five most frequent test for specimen a year before?
select t1.spec_type_desc from ( select microbiologyevents.spec_type_desc, dense_rank() over ( order by count(*) desc ) as c1 from microbiologyevents where datetime(microbiologyevents.charttime,'start of year') = datetime(current_time,'start of year','-1 year') group by microbiologyevents.spec_type_desc ) as t1 where t1.c1 <= 5