在php中，多个Pi图表不显示在单个页面中

我有下面的php代码，其中每件事都很好地工作，并显示了一个饼图

<?php

include "libchart/classes/libchart.php";

header("Content-type: image/png");

$chart = new PieChart(500, 260);
    $con=mysqli_connect("localhost","root","","bkash");

$result = mysqli_query($con,"SELECT count(*) as count FROM dialer_rate where mno='tnr' and trx_result='Success' ");
$result1 = mysqli_query($con,"SELECT count(*) as count1 FROM dialer_rate where mno='tnr' and trx_result='Failed'");
$result = $result->fetch_object();
$result1 = $result1->fetch_object();
$dataSet = new XYDataSet();

$dataSet->addPoint(new Point("Success ($result->count)", $result->count));
$dataSet->addPoint(new Point("Failed ($result1->count1)", $result1->count1));
#$dataSet->addPoint(new Point(" (50)", 50));
$chart->setDataSet($dataSet);

$chart->setTitle("bKash USSD Dialer Success/Fail rate");
$chart->render();
?>

<?php
include "libchart/classes/libchart.php";
header("Content-type: image/png");

$chart = new PieChart(500, 260);
$con=mysqli_connect("localhost","root","","bkash");

$result = mysqli_query($con,"SELECT count(*) as count FROM dialer_rate where mno='tnr' and trx_result='Success' ");
$result1 = mysqli_query($con,"SELECT count(*) as count1 FROM dialer_rate where mno='tnr' and trx_result='Failed'");
$result = $result->fetch_object();
$result1 = $result1->fetch_object();
$dataSet = new XYDataSet();

$dataSet->addPoint(new Point("Success ($result->count)", $result->count));
$dataSet->addPoint(new Point("Failed ($result1->count1)", $result1->count1));
#$dataSet->addPoint(new Point(" (50)", 50));
$chart->setDataSet($dataSet);

$chart->setTitle("bKash USSD Dialer Success/Fail rate");
$chart->render();
?>
<?php
include "libchart/classes/libchart.php";
header("Content-type: image/png");
$chart = new PieChart(500, 260);
$con=mysqli_connect("localhost","root","","bkash");
$result2 = mysqli_query($con,"SELECT count(*) as count2 FROM dialer_rate where mno='air' and trx_result='Success' ");
$result3 = mysqli_query($con,"SELECT count(*) as count3 FROM dialer_rate where mno='air' and trx_result='Failed'");
$result2 = $result2->fetch_object();
$result3 = $result3->fetch_object();
$dataSet = new XYDataSet();
$dataSet->addPoint(new Point("Success ($result2->count)", $result2->count2));
$dataSet->addPoint(new Point("Failed ($result3->count1)", $result3->count3));
#$dataSet->addPoint(new Point(" (50)", 50));
$chart->setDataSet($dataSet);
$chart->setTitle("bKash USSD Dialer Success/Fail rate");
$chart->render();
?>