| Dates | Calls for Decade | Running Total | Yearly Average |
| 1901-1910 | 12 | 12 | 1.2 |
| 1911-1920 | 29 | 41 | 2.9 |
| 1921-1930 | 134 | 175 | 13.4 |
| 1931-1940 | 296 | 471 | 29.6 |
| 1941-1950 | 431 | 902 | 43.1 |
| 1951-1960 | 685 | 1,587 | 68.5 |
| 1961-1970 | 1,302 | 2,889 | 130.2 |
| 1971-1980 | 2,507 | 5,396 | 250.7 |
| 1981-1990 | 6,098 | 11,494 | 609.8 |
| 1991-2000 | 8,707 | 20,201 | 870.7 |
| 2001-2008 | 8,474 | 28,675 | 1,059 |
