Handlebars Reverse Helper

HTML

<script src="http://builds.handlebarsjs.com.s3.amazonaws.com/handlebars-v1.3.0.js"></script>
<script id="template" type="text/x-handlebars-template">
    

    {{#each collections}}
        {{this}}<br />
    {{/each}}
    
</script>
<div id="rendered"></div>

JavaScript

var template = Handlebars.compile($("#template").html());
var collections = {
"2017":[{"postion":0},{"postion":1}],
"2018":[{"postion":0},{"postion":1}]
};
$("#rendered").html(template(
    {
        "collections": {
            "2017": ["1" ]  ,
            "2018": [ "2"]  
        }
    }
));