When was the 750th anniversary of the city in which the 2003 Priority Telecom Open was held?
2003 Priority Telecom Open: The 2003 Priority Telecom Open was a tennis tournament played on outdoor clay courts in Amersfoort, Netherlands and was part of the International Series of the 2003 ATP Tour. Amersfoort:  It marked its 750th anniversary as a city in 2009.
2009