Another hack that, is pretty simple and works, is to close the select tag: <select ... />
Please note />
at the end of first line:
<select th:field="*{percentage}" />
<option th:each="i : ${#numbers.sequence(0, 100)}" th:value="${i}" th:text="${i}" th:selected="${i==75}"></option>
</select>
Renders as:
<select id="percentage" name="percentage" />
<option value="0">0</option>
<option value="1">1</option>
...
<option value="74">74</option>
<option value="75" selected="selected">75</option>
<option value="76">76</option>
...
<option value="100">100</option>
</select>
Both web browser and Thymeleaf will handle this fine.
I used Thymeleaf v.3.0.9.RELEASE