 USD) to calculate poverty measures</p></td>
    </tr>
    <tr>
      <th>year</th>
      <td><p>numeric:  list of years, or `all`, or `last`.</p></td>
    </tr>
    <tr>
      <th>aggregate</th>
      <td><p>logical: `TRUE` will return aggregate results,
`FALSE` country-level results.</p></td>
    </tr>
    <tr>
      <th>fill_gaps</th>
      <td><p>logical: `TRUE` will interpolate / extrapolate values when
surveys are not available for a specific year.</p></td>
    </tr>
    <tr>
      <th>coverage</th>
 