Q9. When you rode a bicycle during the past 12 months,
                 how often did you wear a helmet?
                    (Weighted Column Percents)
 ----------------------------------------------------------------
                           Total               Grade
                                  -------------------------------
                                    9th    10th    11th    12th
 ----------------------------------------------------------------
 I did not ride a bicycle
    during the past 12
    months                   21.3    15.1    19.8    24.7    28.7
 Never wore a helmet         40.5    33.4    40.5    44.6    46.9
 Rarely wore a helmet         8.7    11.0     9.3     7.2     6.0
 Sometimes wore a helmet      7.0     9.2     7.1     6.2     4.3
 Most of the time wore a
    helmet                    9.5    13.4     9.4     7.4     6.4
 Always wore a helmet        13.0    17.9    14.0     9.9     7.7
 Female
   I did not ride a
      bicycle during the
      past 12 months         25.3    19.0    25.0    28.3    31.7
   Never wore a helmet       37.0    30.6    35.5    41.5    43.6
   Rarely wore a helmet       8.5    10.9     9.7     6.7     5.3
   Sometimes wore a
      helmet                  6.7     8.4     7.1     6.0     4.3
   Most of the time wore
      a helmet                9.5    13.1     9.3     7.6     6.8
   Always wore a helmet      13.0    18.0    13.4    10.0     8.3
 Male
   I did not ride a
      bicycle during the
      past 12 months         17.2    11.0    14.7    21.0    25.7
   Never wore a helmet       44.2    36.3    45.4    47.8    50.2
   Rarely wore a helmet       8.9    11.2     8.9     7.7     6.7
   Sometimes wore a
      helmet                  7.2    10.0     7.1     6.4     4.3
   Most of the time wore
      a helmet                9.5    13.6     9.4     7.3     6.0
   Always wore a helmet      13.0    17.8    14.6     9.8     7.1
 ----------------------------------------------------------------
                            Total N =
                              31,481

 
      Q9. When you rode a bicycle during the past 12 months,
                 how often did you wear a helmet?
                     (Unweighted Frequencies)
 ----------------------------------------------------------------
                           Total               Grade
                                  -------------------------------
                                    9th    10th    11th    12th
 ----------------------------------------------------------------
 I did not ride a bicycle
    during the past 12
    months                  7,020   1,548   1,802   1,845   1,825
 Never wore a helmet       13,389   3,322   3,695   3,374   2,998
 Rarely wore a helmet       2,719   1,046     822     500     351
 Sometimes wore a helmet    2,081     829     589     412     251
 Most of the time wore a
    helmet                  2,721   1,172     752     460     337
 Always wore a helmet       3,551   1,517   1,049     599     386
 Female
   I did not ride a
      bicycle during the
      past 12 months        4,242   1,002   1,126   1,093   1,021
   Never wore a helmet      6,195   1,533   1,634   1,613   1,415
   Rarely wore a helmet     1,353     528     419     237     169
   Sometimes wore a
      helmet                1,049     398     314     207     130
   Most of the time wore
      a helmet              1,379     572     375     254     178
   Always wore a helmet     1,798     758     513     314     213
 Male
   I did not ride a
      bicycle during the
      past 12 months        2,778     546     676     752     804
   Never wore a helmet      7,194   1,789   2,061   1,761   1,583
   Rarely wore a helmet     1,366     518     403     263     182
   Sometimes wore a
      helmet                1,032     431     275     205     121
   Most of the time wore
      a helmet              1,342     600     377     206     159
   Always wore a helmet     1,753     759     536     285     173
 ----------------------------------------------------------------
                            Total N =
                              31,481