creating a custom valuelist

Let say I have a table: boekingen
with a field: datumvan (DATETIME)

let say I have 5 records

1-1-2003 18:23
1-2-2003 20:45
1-8-2003 21:56
1-3-2004 00:00
4-5-2005 12:00

Now, with this data, I want to create a valuelist (by doing a query) which is automatic filled with:
2003
2004
2005

Can someone help me with this?

“SELECT DISTINCT datumvan FROM boekingen” is the query. I presume you know the rest :D