• https://www.highcharts.com/demo/line-basic
• Расширение

use miloschuman\highcharts\Highcharts;
use yii\web\JsExpression;
 
$this->registerAssetBundle('yii\web\YiiAsset');
 
echo Highcharts::widget([
   'options' => [
    'title' => ['text' => 'Статистика за месяц'],
    'xAxis' => [
       'categories' => array_keys($statistic)
    ],
    'yAxis' => [
       'title' => ['text' => 'Достижения цели']
    ],
    'series' => [
       ['name' => 'Jane', 'data' => array_values($statistic), 'class'=>'test-class'],
    ],
    'plotOptions' => [
      'series' => [
        'cursor' => 'pointer',
        'point' => [
          'events' => [
            'click' => new JsExpression('function(e){ alert(this.x); }')
          ]
        ]
      ]
    ]
   ]
]);

• Подробнее...

• http://www.flotcharts.org/flot/examples/
• https://github.com/bburim/flot
• https://github.com/borodulin/yii2-flot
• https://github.com/iddqdidkfa/yii2-flot
• https://github.com/machour/yii2-jquery-flot