Revelers wear green wigs during the annual St. Patrick's Parade in Washington D.C., capital of the United States, March 17, 2013. (Xinhua/Zhang Jun)

Girls wave to revelers during the annual St. Patrick's Parade in Washington D.C., capital of the United States, March 17, 2013. (Xinhua/Zhang Jun)

A man drives a mini car during the annual St. Patrick's Parade in Washington D.C., capital of the United States, March 17, 2013. (Xinhua/Zhang Jun)

Revelers dance during the annual St. Patrick's Parade in Washington D.C., capital of the United States, March 17, 2013. (Xinhua/Zhang Jun)

People attend the celebration of St. Patrick's Day at Trafalgar Square in London, March 17, 2013. (Xinhua/Bimal Gautam)

People attend the celebration of St. Patrick's Day at Trafalgar Square in London, March 17, 2013. (Xinhua/Bimal Gautam)

A man dressed in green balloons attends the celebration of St. Patrick's Day at Trafalgar Square in London, March 17, 2013. (Xinhua/Bimal Gautam)

People attend the celebration of St. Patrick's Day at Trafalgar Square in London, March 17, 2013. (Xinhua/Bimal Gautam)

A clown entertains public during the annual St. Patrick's Day Parade in Vancouver, Canada, March 17, 2013. Thousands of people have crowded downtown Vancouver to watch as bagpipers, Irish dancers and hurlers paraded with dreadlocked dancers, green samba queens, and even a roller derby team took part in the 9th annual St. Patrick's Day parade. The festivities continue the centuries-old custom of partying on the saint's feast day, March 17, to honour his role of helping convert the Irish to the Catholic faith. (Xinhua/Sergei Bachlakov)

Spectators watch the annual St. Patrick's Day Parade in Vancouver, Canada, March 17, 2013. Thousands of people have crowded downtown Vancouver to watch as bagpipers, Irish dancers and hurlers paraded with dreadlocked dancers, green samba queens, and even a roller derby team took part in the 9th annual St. Patrick's Day parade. The festivities continue the centuries-old custom of partying on the saint's feast day, March 17, to honour his role of helping convert the Irish to the Catholic faith. (Xinhua/Sergei Bachlakov)

A hockey fan participates in the annual St. Patrick's Day Parade in Vancouver, Canada, March 17, 2013. Thousands of people have crowded downtown Vancouver to watch as bagpipers, Irish dancers and hurlers paraded with dreadlocked dancers, green samba queens, and even a roller derby team took part in the 9th annual St. Patrick's Day parade. The festivities continue the centuries-old custom of partying on the saint's feast day, March 17, to honour his role of helping convert the Irish to the Catholic faith. (Xinhua/Sergei Bachlakov)

Vancouver Police Pipe Band march through the streets during the annual St. Patrick's Day Parade in Vancouver, Canada, March 17, 2013. Thousands of people have crowded downtown Vancouver to watch as bagpipers, Irish dancers and hurlers paraded with dreadlocked dancers, green samba queens, and even a roller derby team took part in the 9th annual St. Patrick's Day parade. The festivities continue the centuries-old custom of partying on the saint's feast day, March 17, to honour his role of helping convert the Irish to the Catholic faith. (Xinhua/Sergei Bachlakov)

 A bus drives during the annual St. Patrick's Day Parade in Vancouver, Canada, March 17, 2013. Thousands of people have crowded downtown Vancouver to watch as bagpipers, Irish dancers and hurlers paraded with dreadlocked dancers, green samba queens, and even a roller derby team took part in the 9th annual St. Patrick's Day parade. The festivities continue the centuries-old custom of partying on the saint's feast day, March 17, to honour his role of helping convert the Irish to the Catholic faith. (Xinhua/Sergei Bachlakov)

Fiddlers entertain public during the annual St. Patrick's Day Parade in Vancouver, Canada, March 17, 2013. Thousands of people have crowded downtown Vancouver to watch as bagpipers, Irish dancers and hurlers paraded with dreadlocked dancers, green samba queens, and even a roller derby team took part in the 9th annual St. Patrick's Day parade. The festivities continue the centuries-old custom of partying on the saint's feast day, March 17, to honour his role of helping convert the Irish to the Catholic faith. (Xinhua/Sergei Bachlakov)

Colorfully dressed women participate in the annual St. Patrick's Day Parade in Vancouver, Canada, March 17, 2013. Thousands of people have crowded downtown Vancouver to watch as bagpipers, Irish dancers and hurlers paraded with dreadlocked dancers, green samba queens, and even a roller derby team took part in the 9th annual St. Patrick's Day parade. The festivities continue the centuries-old custom of partying on the saint's feast day, March 17, to honour his role of helping convert the Irish to the Catholic faith. (Xinhua/Sergei Bachlakov)