I am having a multiselect dropdown as below

```
<select id="year" multiple ng-model="type"  ng-disabled="!type1" >
    <option value="all" selected>all</option>
    <option value='2012'>2012</option>
    <option value='2013'>2013</option>
    <option value='2014'>2014</option>
    <option value='2015'>2015</option>
    <option value='2016'>2016</option>
    <option value='2017'>2017</option>
    <option value='2018'>2018</option>
    <option value='2019'>2019</option>
</select>

```

I want to set option "all" as a default value. For that I wrote "selected" keyword inside the option tag, which I want to appear by default in my drop down list as you can see in the above code. But it is not working . Can anyone please help me how can i set the default value.