Evidence of Impact of decreased taxation on rates of initial smoking experimentation and onset of daily smoking.

*Tests the contrast that the estimated rates for the years 1993 through 1998 differs from 1990 (the reference year).
†Tests the contrast that the estimated rate for the years 1993 through 1998 is the same in each year and that this common estimate differs from 1990 (the reference year).
¶Tests the hypothesis that the annual rates between 1993 and 1998 differ from the estimate common value (the difference between the previous two chi-square values).