How to set Form API date_select option values
This is how I get when I copied your code without any change. Option values are correct, but somehow the order got reversed.

&lt;select class="date-year form-select" id="edit-birth-date-year" name="birth_date[year]"&gt;
    &lt;option value="" selected="selected"&gt;-Year&lt;/option&gt;
    &lt;option value="1910"&gt;1910&lt;/option&gt;
    &lt;option value="1911"&gt;1911&lt;/option&gt;
    &lt;option value="1912"&gt;1912&lt;/option&gt;
    .
    .
    .
    &lt;option value="2017"&gt;2017&lt;/option&gt;
&lt;/select&gt;


Check your Date / Date API module versions. I'm using 7.x-2.8