Compare newest rows from same table
SELECT * FROM
        (SELECT empID, ssn, fname, minitial, lname, email, dob,
         gender, wkPh, maritalStatus,
         ROW_NUMBER() OVER (PARTITION BY empID ORDER BY lastUpdate DESC)
                 AS ranking
         FROM empHistory  WHERE (benYr = 2011))
     T WHERE ranking=1

SELECT empID, ssn, fname, minitial, lname, email, dob, gender, wkPh, maritalStatus, benYr FROM empHistory AS a WHERE (benYr = '2011') AND (lastUpdate = (SELECT MAX(lastUpdate) AS Expr1 FROM empHistory AS b WHERE (a.empID = empID)))