It is one of the most affluent counties in the nation , and has the highest percentage -LRB- NUMBER@1 % -RRB- of residents over NUMBER@2 years old who hold a post-graduate degree .

It is one of the richest counties in the LOCATION@1 -LSB- -RSB- , and has the highest percentage -LRB- NUMBER@1 % -RRB- of residents over NUMBER@2 years old who hold a post-graduate degree .
