Material Line with ticks problemns

[rafael nunes]

Good evening, I'm trying to set up the vertical axis of the chart, but the ticks option is not working. How do I make it work in this type of graphic?

    google.charts.load('current', {'packages':['line','bar']});
    google.charts.setOnLoadCallback(drawTable);
    google.charts.setOnLoadCallback(drawTable2);

    function drawTable(){
        $.ajax({
            url: "php/loadDadosCurvaABCServicos.php",
            data: {idOrcamento:idOrcamento, idObra:idObra},
            dataType: "json",
            async: false,
            success: function(jsonData){
                var data = new google.visualization.DataTable(jsonData);          
                var chart = new google.charts.Line(document.getElementById('chart_div1'));
                var options = {
                    legend: {
                        position: 'none',
                        alignment: 'center'
                    },
                    vAxis: {
                        format: 'percent',
                        ticks: [0, .2, .4, .6, .8, 1],                        
                        title: 'Percentagem Acumulada'
                    },
                    //focusTarget: 'category',
                    tooltip: { isHtml: true },
                    width: 1200,
                    height: 600                   
                };
                chart.draw(data, google.charts.Line.convertOptions(options));                
            }
        }).responseText;
    }