The calendar used in Australia and in most other countries was introduced by Pope Gregory XIII in 1582. It provides for 366 days in those years for which the year number when divided by 4 gives a whole number (i. e. without a remainder), those years are called leap years. All other years have 365 days. The Gregorian calendar further specifies that years whose year number is divisible evenly by 100 are not leap years, unless the year number is also divisible by 400. In a leap year February has 29 days, whereas in a non-leap year it has 28 days. A decade is a 10-year period, such as I January 1885--31 December 1894. Which one of the following years was a leap year?