gistfile1.sql

SELECT 
	date_part('year', age('2010-12-1',birthday)),
	count(date_part('year', age('2010-12-1',birthday)))
FROM
	member
GROUP BY
	date_part('year', age('2010-12-1',birthday))
ORDER BY
	date_part('year', age('2010-12-1',birthday))

 date_part | count
-----------+-------
        29 |     1
        30 |     4
        31 |     2
        32 |    11
・・・・
       107 |     2
       108 |     1
       114 |     1