Frequencies for year variable in oprev0to992004_2014 dataset :

       Year |      Freq.     Percent        Cum.
------------+-----------------------------------
       2004 |        460        9.09        9.09
       2005 |        460        9.09       18.18
       2006 |        460        9.09       27.27
       2007 |        460        9.09       36.36
       2008 |        460        9.09       45.45
       2009 |        460        9.09       54.55
       2010 |        460        9.09       63.64
       2011 |        460        9.09       72.73
       2012 |        460        9.09       81.82
       2013 |        460        9.09       90.91
       2014 |        460        9.09      100.00
------------+-----------------------------------
      Total |      5,060      100.00

by Jean Roth , jroth@nber.org , 14 Mar 2018