On load Google LineChart animation

I'm trying to implement loading animation of chart using transition animations by adding rows and refreshing the chart. But it behaves completely differently from what I expect. Here is the Fiddle http://jsfiddle.net/jATUX/ Some code:

google.load('visualization', '1', { packages: ['corechart'], callback: function() {
        var data = new google.visualization.DataTable();
        data.addRows(5);

        data.addColumn('string', '');
        data.addColumn('number', 'Sales');

        var options = {
            title: 'Sales by months for 2013 year', curveType: 'function',
            "vAxis": { "minValue": "0" }, "hAxis": { "slantedTextAngle": "45", "slantedText": "true" }, "legend": { "position": "top" }, "pointSize": "5",
            animation: { duration: 1000 }
        };
        var chart = new google.visualization.LineChart(document.getElementById('test'));

        var index = 0;
        var chartData = [
            ['Jan', 5 ], ['Feb', 1], ['Mar', 4], ['Apr', 2], ['May', 3]
        ]
        var drawChart = function() {
            console.log('drawChart index ' + index);
            if (index < chartData.length) {
                data.addRows([chartData[index++]]);
                chart.draw(data, options);
            }
        }

        google.visualization.events.addListener(chart, 'ready', drawChart);
        chart.draw(data, options);
    }});

Ok, I've managed to solve that. It's all a matter of using 'animationfinish' That now looks like http://jsfiddle.net/HDu8H/ or

google.load('visualization', '1', { packages: ['corechart'], callback: function() {
        var data = new google.visualization.DataTable();
        data.addRows(5);

        data.addColumn('string', '');
        data.addColumn('number', 'Sales');
        data.addRows(5);
        data.setValue(0, 0, 'Jan');
        data.setValue(1, 0, 'Feb');
        data.setValue(2, 0, 'Mar');
        data.setValue(3, 0, 'Apr');
        data.setValue(4, 0, 'May');

        var options = {
            title: 'Sales by months for 2013 year', curveType: 'function',
            "vAxis": { "minValue": "0", "maxValue": 6 }, "hAxis": { "slantedTextAngle": "45", "slantedText": "true" }, "legend": { "position": "top" }, "pointSize": "5",
            animation: { duration: 250 }
        };
        var chart = new google.visualization.LineChart(document.getElementById('test'));

        var index = 0;
        var chartData = [ 5, 1, 4, 2, 3 ]
        var drawChart = function() {
            console.log('drawChart index ' + index);
            if (index < chartData.length) {
                data.setValue(index, 1, chartData[index++]);
                chart.draw(data, options);
            }
        }

        google.visualization.events.addListener(chart, 'animationfinish', drawChart);
        chart.draw(data, options);
        drawChart();
    }});