Eighty thousand people attended The University of Texas versus Texas AM football game. The fans of both teams were so happy, they decided to...

Eighty thousand people attended The University of Texas versus Texas A&M football game. The fans of both teams were so happy, they decided to organize a party each day for a year. They decided that on each day, anyone with their birthday on that day would return to the stadium at noon to celebrate. Why would at least one party have more than 200 people?