Only 2 popes in the past millennium have made it past the 25-year mark: Piux IX (1846-1878) and Leo XIII (1878-1903), the latter with just a few months to spare. Two other popes fell just short: Pius VI (24 years, 6 months and 14 days) and Pius VII (23 years, 5 months and 16 days). John Paul II is now at 23 years and 7 months.
He's in no condition to celebrate.