ubsubheading" id="Description-62"><span>Description<a class="copiable-link" href="#Description-62"> &para;</a></span></h4>

<p>Monthly mean relative sunspot numbers from 1749 to 1983. Collected at Swiss
Federal Observatory, Zurich until 1960, then Tokyo Astronomical Observatory.
</p>
<h4 class="subsubheading" id="Format-61"><span>Format<a class="copiable-link" href="#Format-61"> &para;</a></span></h4>

<dl class="table">
<dt><code class="code">month</code></dt>
<dd><p>Month of the observation.
</p></dd>
<dt