Year | Non-iodized salt group | Low-iodine salt group | High-iodine salt group | χ2 | P | |||
---|---|---|---|---|---|---|---|---|
N (%) | Tvol | N (%) | Tvol | N (%) | Tvol | |||
1999 | 69 (5.5) | 1.2 (0.9,1.5) | 215 (17.2) | 1.1 (0.9,1.4) | 968 (77.3) | 1.2 (1.0,1.6) | 9.2 | 0.010 |
2005 | 17 (1.4) | 2.4 (2.1,2.7) | 247 (20.2) | 2.4 (2.2,2.8) | 959 (38.8) | 2.4 (2.2,2.7) | 0.7 | 0.700 |
2011 | 95 (7.7) | 1.0 (0.8,1.2) | 660 (53.5) | 1.0 (0.8,1.1) | 479 (16.9) | 1.0 (0.8,1.2) | 0.3 | 0.865 |
2014 | 217 (14.4) | 1.9 (1.3,2.4) | 1038 (68.7) | 1.8 (1,2.5) | 255 (16.9) | 1.8 (1.1,2.5) | 0.8 | 0.659 |
2017 | 283 (23.4) | 2.6 (1.8,3.5) | 846 (70.0) | 2.8 (2,3.7) | 80 (6.6) | 3.1 (1.6,4.0) | 2.1 | 0.348 |