Aperture & libraries
You can export folder (in your example 2009) as a library. This self contained library can be stored where you like and once reattached it is very easy to switch libraries from within Aperture. The only shortcoming of this is that images from 2009 are only available when that library is open.
|Hot Air Balloons Over Bagan by User9320321874|
|Blue mood by darub|
from Fixed lens shootout.
|Yellow Warbler by LeeS|
from A Big Year - birds
|Waiting for the Parade by tcoker1103|
from - La Vida Loca - (Black and White Street Photography+ A Border)