Table 3 Prevalence (%) of respiratory symptoms and asthma by study year, age group and sex

1996

12.8

11.5

8.9

7.2

10.5

<0.001

10.4

9.7

0.318

10.1

10.1

2006

18.3

14.0

12.6

12.5

10.9

<0.001

14.3

12.2

0.016

13.3

13.4

<0.001

1996

11.8

10.1

7.7

6.8

10.7

0.016

9.4

9.3

0.899

9.3

9.4

2006

15.6

12.1

10.8

10.6

9.5

<0.001

12.4

10.5

0.020

11.5

11.6

<0.001

1996

11.8

11.8

9.5

10.0

11.7

0.395

12.2

9.7

0.001

10.9

10.9

2006

14.1

11.9

11.7

12.6

12.0

0.315

13.7

11.0

0.001

12.4

12.4

0.009

1996

13.0

12.0

12.0

11.9

13.3

0.883

13.6

11.2

0.002

12.4

12.4

2006

10.6

9.0

9.1

11.1

10.7

0.334

11.0

9.2

0.017

10.1

10.1

<0.001

1996

19.9

19.4

15.8

19.1

22.0

0.296

19.0

19.2

0.830

19.1

19.0

2006

18.6

14.1

12.2

15.4

15.4

0.288

14.7

15.2

0.551

15.0

15.0

<0.001

1996

4.9

5.9

5.7

9.3

11.9

<0.001

7.1

7.8

0.260

7.4

7.3

2006

6.1

5.1

5.5

6.8

7.7

0.017

5.3

7.3

0.001

6.3

6.2

0.009

1996

18.4

19.1

16.5

19.0

20.3

0.295

19.6

17.6

0.030

18.6

18.5

2006

20.8

17.7

17.5

19.7

17.6

0.317

19.0

18.2

0.423

18.6

18.6

0.974

1996

12.1

13.6

12.2

13.8

15.6

0.021

14.1

12.8

0.119

13.4

13.4

2006

10.3

11.1

11.8

13.8

12.3

0.030

11.9

12.2

0.765

12.1

12.0

0.019

1996

7.8

7.8

6.3

8.1

9.6

0.117

7.6

8.1

0.446

7.9

7.8

2006

8.3

5.8

7.3

8.2

7.1

0.857

7.6

7.2

0.519

7.4

7.4

0.305