plot</a></span><span class="op">(</span><span class="fu">expit</span><span class="op">(</span><span class="va">pred</span><span class="op">)</span> <span class="op">+</span> <span class="fu">expit</span><span class="op">(</span><span class="va">low</span><span class="op">)</span> <span class="op">+</span> <span class="fu">expit</span><span class="op">(</span><span class="va">upp</span><span class="op">)</span> <span class="op">~</span> <span class="va">year</span> <span class="op">|</span> <span class="va">