4 = quite a bit</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 12                                                              1 =medium</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 14                                                                   &lt;NA&gt;</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 15                                                    -9999=missing value</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 16                  