Причины медленной работы api яндекс метрики на php?

class APImetrika{

	private $token 	    = YA_TOKEN;
	private $url_api    = "https://api-metrika.yandex.ru/";
	private $counter_id = YA_ID;

	public function get_traffic($date1, $date2){

		return $this->get_data(
			$this->url_api.
			"stat/v1/data?id=".
			$this->counter_id.
			"&metrics=ym:s:users,ym:s:visits,ym:s:pageviews".
			"&pretty=1".
			"&date1=".$date1.
			"&date2=".$date2.
			"&oauth_token=".
			$this->token
		);
	}

	private function get_data($url){

		if($url){

			$ch = curl_init();
			curl_setopt($ch, CURLOPT_URL, $url);
			curl_setopt($ch, CURLOPT_HEADER, 0);
			curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
			curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);
			curl_setopt($ch, CURLOPT_TIMEOUT, 30);
			curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

			$data = json_decode(
				curl_exec($ch), true
			);

			curl_close($ch);

			if(is_array($data)){

				return $data;
			}
		}

		return false;
	}
}

$obj = new APImetrika();

$today = $obj->get_traffic(
	date("Ymd"),
	date("Ymd")
);
$last  = $obj->get_traffic(
	date("Ymd", strtotime("-1 days")),
	date("Ymd", strtotime("-1 days"))
);

$last2  = $obj->get_traffic(
	date("Ymd", strtotime("-2 days")),
	date("Ymd", strtotime("-2 days"))
);

$last3  = $obj->get_traffic(
	date("Ymd", strtotime("-3 days")),
	date("Ymd", strtotime("-3 days"))
);

$last4  = $obj->get_traffic(
	date("Ymd", strtotime("-4 days")),
	date("Ymd", strtotime("-4 days"))
);

$last5  = $obj->get_traffic(
	date("Ymd", strtotime("-5 days")),
	date("Ymd", strtotime("-5 days"))
);

$last6  = $obj->get_traffic(
	date("Ymd", strtotime("-6 days")),
	date("Ymd", strtotime("-6 days"))
);

if ($('#traffic-chart').length) {
        var chart = new Chartist.Line('#traffic-chart', {
            labels: ['<?=date("d.m.y", strtotime("-6 days"));?>',
			'<?=date("d.m.y", strtotime("-5 days"));?>', 
			'<?=date("d.m.y", strtotime("-4 days"));?>', 
			'<?=date("d.m.y", strtotime("-3 days"));?>', 
			'<?=date("d.m.y", strtotime("-2 days"));?>', 
			'<?=date("d.m.y", strtotime("-1 days"));?>', 
			''],
            series: [
            [<?php echo($last6["totals"][0]);?>, <?php echo($last5["totals"][0]);?>, <?php echo($last4["totals"][0]);?>, <?php echo($last3["totals"][0]);?>, <?php echo($last2["totals"][0]);?>, <?php echo($last["totals"][0]);?>, <?php echo($today["totals"][0]);?>],
            [<?php echo($last6["totals"][1]);?>, <?php echo($last5["totals"][1]);?>, <?php echo($last4["totals"][1]);?>, <?php echo($last3["totals"][1]);?>, <?php echo($last2["totals"][1]);?>, <?php echo($last["totals"][1]);?>, <?php echo($today["totals"][1]);?>],
            [<?php echo($last6["totals"][2]);?>, <?php echo($last5["totals"][2]);?>, <?php echo($last4["totals"][2]);?>, <?php echo($last3["totals"][2]);?>, <?php echo($last2["totals"][2]);?>, <?php echo($last["totals"][2]);?>, <?php echo($today["totals"][2]);?>]
            ]
        }, {
            low: 0,
            showArea: true,
            showLine: false,
            showPoint: false,
            fullWidth: true,
            axisX: {
                showGrid: false
            }
        });

        chart.on('draw', function(data) {
            if(data.type === 'line' || data.type === 'area') {
                data.element.animate({
                    d: {
                        begin: 2000 * data.index,
                        dur: 2000,
                        from: data.path.clone().scale(1, 0).translate(0, data.chartRect.height()).stringify(),
                        to: data.path.clone().stringify(),
                        easing: Chartist.Svg.Easing.easeOutQuint
                    }
                });
            }
        });
    }