nk or set well before start date (i.e.
<code>1800</code>) to use from the first year of the source data.</p></dd>


<dt>end_year</dt>
<dd><p>Numeric value of the last year to consider for analysis. Leave blank or set well after end date (i.e.
<code>2100</code>) to use up to the last year of the source data.</p></dd>


<dt>exclude_years</dt>
<dd><p>Numeric vector of years to exclude from analysis. Leave blank or set to <code>NULL</code> to include all years.</p></dd>


<dt>months</dt>
<dd><p>Numeric vector o