t co"><span class="r-pr">#&gt;</span> 'data.frame':	100 obs. of  36 variables:</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  $ year    : int  1987 1990 1987 1990 1987 1990 1987 1990 1987 1990 ...</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  $ lowbrth : num  8 8.4 4.8 4.8 6.4 ...</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  $ infmort : num  12.2 10.8 10.4 10.5 9.5 ...</span>
<span class="r-out co"><span class="r-pr">#&gt;</span>  $ afdcprt : int  132 132 1