Characteristics of 12,136 pupils that sat Key Stage tests in 2002 to 2005.

KS 1 sat aged 7, KS 2 sat aged 11, KS 3 sat aged 14.SD = standard deviation.range = 10th to 90th percentile.BTS = British Thoracic Society.active asthma = bronchodilator in period 12 months before Key Stage test.inactive asthma = no bronchodilator in period 12 months before Key Stage test.† = in period 3 m prior to KS test.‡ = in period 12 m prior to KS test.*Council Tax band based on property valuation on 1st April 1991.NA = not available.