ChartJS - Line Chart - Y axis scale problem ?

Line Chart - Y axis scale problem ?

HTML

<script src="http://www.chartjs.org/assets/Chart.js"></script>
<body>
  <canvas id="chart"></canvas>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.5.0/Chart.min.js"
        integrity="sha256-GcknncGKzlKm69d+sp+k3A2NyQE+jnu43aBl6rrDN2I=" crossorigin="anonymous"></script>

</body>

JavaScript

// Chart
var ctx = document.getElementById("chart");
var options = {
    type: 'line',
    data: {
        labels: ["1", "2", "4", "6", "7", "10"],
        datasets: [
            {
                backgroundColor: "rgba(151,187,205,0.2)",
                borderColor: "rgba(151,187,205,1)",
                data: [80, 80, 80, 80, 80, 80]
            },
            {
                backgroundColor: "rgba(220,220,220,0.2)",
                borderColor: "rgba(220,220,220,1)",
                data: [8.84, 17.68, 35.36, 53.04, 70.72, 88.4]
            }
        ]
    },
    options: {
        tooltips: {
            enabled: false
        },
        legend: {
            position: 'top'
        }
    }
};
var myChart = new Chart(ctx, options);