( CNN ) -- When you suit up in green on Sunday and head to the St. Patrick 's Day parade or your favorite Irish bar to celebrate , dropping these facts and figures about the holiday 's origins will impress your fellow revelers ! 5 : St. Patrick 's Day began as a religious holiday to honor the saint who , in the fifth century , introduced Christianity to Ireland . 1762 : The first St. Patrick 's Day parade happened in New York on March 17 , 1762 . 133 million : People in the U.S. who plan to celebrate St. Patrick 's Day in 2013 . 84.2 % : Percentage of those celebrating who plan to wear green . $ 4.7 billion : Expected St. Patrick 's Day spending in 2013 . 2,900 : Species of snakes . According to legend , St. Patrick drove all of the snakes from Ireland . 1 in 10,000 : Occurrence of a white four-leaf clover for every common three-leaved clover . 40 : Pounds of dye needed to turn the Chicago River green for the city 's St. Patrick 's Day parade . 7 : Places in the U.S. named Shamrock . 13 : Places in the U.S. named Dublin . 17-641 : Pantone number for emerald , the 2013 Pantone color of the year . 6 : Movies in the original `` Leprechaun '' franchise . Jennifer Aniston had one of her first starring roles in the original `` Leprechaun , '' released in 1993 . A reboot is planned for possible release this year . 4 : Ireland 's global rank in beer consumption per capita in 2011 , with 101.1 liters . 15 : The U.S. rank in beer consumption per capita , with 76.6 liters . 34.5 million : People in the U.S. with Irish ancestry , as of 2011 . 530 : Calories in a 12-ounce McDonald 's limited-edition green Shamrock Shake .
Irish could spend $ 4.7 billion celebrating St. Patrick 's Day this year . Jennifer Aniston green is the 2013 Pantone color of the year . With almost 35 million citizens of Irish ancestry , U.S. remembers St. Patrick 's in town names .