970</span>, <span class="va">fit</span><span class="op">$</span><span class="va">smoothed</span><span class="op">$</span><span class="va">level</span>, type <span class="op">=</span> <span class="st">'l'</span><span class="op">)</span></span>
<span><span class="fu"><a href="https://rdrr.io/r/graphics/lines.html" class="external-link">lines</a></span><span class="op">(</span><span class="fl">1871</span><span class="op">:</span><span class="fl">1970</span>, <span class="va">fit</span><span class="op">$</span>