get number of closed questions from stackoverflow for a certain tag

gistfile1.js

function showStats(tag_name) {
    var script = document.createElement("scr" + "ipt");
    script.src = "https://api.stackexchange.com/2.0/questions?fromdate=1336780800&todate=1339459200&order=desc&sort=activity&tagged=" + tag_name + "&site=stackoverflow&callback=renderStats";
    console.log(script);
    $('body').append( script );
}

window.renderStats=function( json ) {
    var num_closed = 0;
    for(var i = -1, l = json.items.length; ++i < l; ) {
        var item = json.items[i];
        if(item.is_answered) {
            num_closed++;
        }
    }
    $('#stats').html( num_closed + " questions answered in last 30 days");
};
        
showStats('ruby-on-rails');