Percentage of packs of cigarettes sold to minors over time
| Time 1 August 1994 | Time 2 August 1995 | Time 3 August 1996 | Time 4 March 1998 | Time 5 January 1999 | χ2 Analyses of differences by time period |
| 41.2% | 32.3% | 34.7% | 12.7% | 15.2% | Time 1 > 2 = 3 > 4 = 5 |
Overall χ2 (df 4) = 197.44, p = 0.0005; time 1 v time 2 χ2 (df 1) = 5.85, p = 0.016; time 2v time 3 χ2 (df 1)= 0.38, p = 0.54; time 2 v time 4 χ2 (df 1) = 56.02, p = 0.0005; time 4v time 5 χ2 (df 1)= 2.10, p = 0.15.