| < 1980 | 1980–1990 | 1991–1995 | 1996–2000 | 2001–2003 | 2004–2006 | 2007–2009 | 2010–2012 | 2017 |
---|---|---|---|---|---|---|---|---|---|
Districts of surveillance | 22 (36/162) | 16 (26/162) | 10 (17/162) | 27 (44/162) | 18 (157/884) | 26 (169/653) | 37 (258/691) | 50 (471/933) | 75 (171/227) |
Cantons | 58 (14/24) | 33 (8/24) | 17 (4/24) | 50 (12/24) | 50 (13/26) | 58 (14/24) | 68 (17/25) | 91 (21/23) | 96 (25/26) |
Subregions | 100 (10/10) | 80 (8/10) | 60 (6/10) | 81 (9/11) | 72 (8/11) | 81 (9/11) | 100 (11/11) | 100 (11/11) | 100 (11/11) |