1990, 7 EU Member States; 1991 to 1994, 12 EU Member States; 1995-96, 14 EU Member States; 1997 to 2003, 15 EU Member States; 2004, 21 EU Member States; 2005-06, 25 EU Member States; 2007 to 2010, 27 EU Member States

References and footnotes