SQL Server 2008 usando
COUNT() OVER
select *, c = count(1) over (partition by zip)
from tbl
order by c desc;
Se você não precisar ver a coluna adicional, poderá mover o
COUNT() OVER
cláusula na cláusula ORDER BY. select JobCode, Job1, Job2, Job3, zip
from tbl
order by count(1) over (partition by zip) desc;