align: middle;
    }

    .dataframe tbody tr th {
        vertical-align: top;
    }

    .dataframe thead th {
        text-align: right;
    }
</style>
<table border="1" class="dataframe">
  <thead>
    <tr style="text-align: right;">
      <th></th>
      <th>dbn</th>
      <th>grade</th>
      <th>category</th>
      <th>number_tested</th>
      <th>mean_scale_score</th>
      <th>level_1_n</th>
      <th>level_1_pct</th>
      <th>level_2_n</th>
      <th>level_2_pct</th>
      <th>level_3_n</th>
    