In 1956, the U.S. states and Canadian provinces came to an agreement with the American Association of Motor Vehicle Administrators, the Automobile Manufacturers Association and the National Safety Council that standardized the size for license plates for vehicles with standardized mounting holes. The first Texas license plate that complied with these standards was introduced towards the end of that year. The plate had two Letters followed by 4 numbers. How many plate numbers could Texas assign in 1956?