 class="r-out co"><span class="r-pr">#&gt;</span>    V1 V1.1 V2 V2.1 V3 V3.1 V4</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1   o    X  o    X  o    X  o</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2   o    X  o    X  o    X  o</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3   o    X  o    X  o    X  o</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 4   o    X  o    X  o    X  o</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 5 