Min & Max percent in T-SQL

--top 20%
SELECT min(percent_outbound_calls)
FROM (SELECT TOP 20 PERCENT percent_outbound_calls
FROM scorecard_outlier
ORDER BY percent_outbound_calls desc)A


--bottom 20%
SELECT max(percent_outbound_calls)
FROM (SELECT TOP 20 PERCENT percent_outbound_calls
FROM scorecard_outlier
ORDER BY percent_outbound_calls asc)A