id="examples"><a class="anchor" href="#examples"></a>Examples</h2>
    <pre class="examples"><div class='input'><span class='fu'><a href='https://rdrr.io/r/utils/data.html'>data</a></span>(<span class='no'>mpdta</span>)
<span class='no'>dta</span> <span class='kw'>&lt;-</span> <span class='fu'><a href='https://rdrr.io/r/base/subset.html'>subset</a></span>(<span class='no'>mpdta</span>, <span class='no'>year</span><span class='kw'>==</span><span class='fl'>2007</span>)
<span class='no'>X</span> <span class='