Highchart not load JSON data - php

Question

I have a page that uses highcharts pie chart with JSON data in it, My chart is not showing in browser but json data is showing like this :
[{"type":"pie","name":"Progress Fisik","data":[["rencana",89.4554],["realisasi",82.1436]]}]
Here my chart.js:
$(document).ready(function() {
var options = {
chart: {
renderTo: 'donut_chart',
plotBackgroundColor: null,
plotBorderWidth: null,
plotShadow: false
},
credits: {
enabled: false
},
exporting: {
enabled: false
},
title: {
text: 'Progres Fisik',
align: 'center',
verticalAlign: 'middle'
},
plotOptions: {
pie: {
allowPointSelect: false,
startAngle: 180,
innerSize: '70%',
cursor: 'pointer',
dataLabels: {
enabled: true,
color: '#000000',
connectorColor: '#000000',
formatter: function() {
return '<b>' + this.point.name+ '</b> : '+ this.point.y;
}
}
}
},
series: [{
type: 'pie',
innerSize: '50%',
colorByPoint: true,
data: []
}]
}
$.getJSON("data.php", function(json) {
options.series = json;
chart = new Highcharts.Chart(options);
});
});
And Here data.php :
include 'db-config.php';
$balai = mysqli_real_escape_string($config, $_GET['balai']);
$query = mysqli_query($config, "SELECT* FROM data_balai WHERE kode_balai='$balai'");
$rows['type'] = 'pie';
$rows['name'] = 'Progress Fisik';
while ($r = mysqli_fetch_assoc($query)) {
$rows['data'][0] = array('rencana', $r['ren_fisik']);
$rows['data'][1] = array('realisasi', $r['real_fisik']);
}
$rslt = array();
array_push($rslt, $rows);
print json_encode($rslt, JSON_NUMERIC_CHECK);
mysqli_close($config);
What do i need to do to fix my code above?