July 25, 1990: 1,000 January 3, 1992: 2,000 February 29, 1992: 3,000 March 30, 1992: 4,000 October 8, 1999: 5,000 February 11, 2000: 6,000 June 20, 2005: 7,000 September 8, 2005: 8,000 November 28, 2005: 9,000 February 6, 2006: 10,000 March 21, 2006: 11,000 April 20, 2006: 12,000 October 30, 2006: 13,000 December 5, 2006:14,000 July 6, 2007: 15,000