SELECT T1.age FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name  =  T2.friend WHERE T2.name =  'Zach' AND T2.year  =  (SELECT max(YEAR) FROM PersonFriend WHERE name =  'Zach')
What are the ages of all of Zach's friends who are in the longest relationship?
[Schema (values) (types)]: | network_2 |  Person : name (text) , age (text) , city (number) , gender (text) , job (text) | PersonFriend : name (text) , friend (text) , year (number);