>
<tr><td style="width: 25%;"><a href="ability.cov.html">ability.cov</a></td>
<td>Ability and Intelligence Tests</td></tr>
<tr><td style="width: 25%;"><a href="airmiles.html">airmiles</a></td>
<td>Passenger Miles on Commercial US Airlines, 1937-1960</td></tr>
<tr><td style="width: 25%;"><a href="AirPassengers.html">AirPassengers</a></td>
<td>Monthly Airline Passenger Numbers 1949-1960</td></tr>
<tr><td style="width: 25%;"><a href="airquality.html">airquality</a></td>
<td>New York Air Quality Measurements</t