dynamic rowspan in jinji
<div class="table-responsive">
  <table class="table table-bordered">
    <thead>
      <tr>
        <th>Year</th>
        <th>Month</th>
        <th>Name</th>
      </tr>
    </thead>
    <tbody>
      {% for yr in yrs %}
        {% set yr_loop = loop %}
        {% for month in months[loop.index0] %}
          {% set month_loop = loop %}
          {% for name in names[yr_loop.index0][loop.index0] %}
            <tr>
              {% if loop.first %}
                {% if month_loop.first %}
                  <td rowspan="{{ names[yr_loop.index0]|sum(start=[])|count }}">{{ yr }}</td>
                {% endif %}
                <td rowspan="{{ loop.length }}">{{ month }}</td>
              {% endif %}
              <td>{{ name }}</td>
            </tr>
        {% endfor %}
      {% endfor %}
    </tbody>
  </table>
<div>
