| Date | Cost |
| 1898 | 1 cent |
| Jan 1, 1952 | 2 cents |
| Aug 1, 1958 | 3 cents |
| Jan 7, 1963 | 4 cents |
| Jan 7, 1968 | 5 cents |
| May 16, 1971 | 6 cents |
| Mar 2, 1974 | 8 cents |
| Sep 14, 1975 | 7 cents |
| Dec 31, 1975 | 9 cents |
| May 29, 1978 | 10 cents |
| Mar 22, 1981 | 12 cents |
|
| Date | Cost |
| Nov 1, 1981 | 13 cents |
| Feb 17, 1985 | 14 cents |
| Apr 3, 1988 | 15 cents |
| Feb 3, 1991 | 19 cents |
| Jan 1, 1995 | 20 cents |
| Jan 10, 1999 | 20 cents |
| Jan 7, 2001 | 20 cents |
| Jul 1, 2001 | 21 cents |
| Jun 30, 2002 | 23 cents |
| Jan 8, 2006 | 24 cents |
| May 14, 2007 | 26 cents |
|