Controller/Adminhtml/Dashboard/Historic.php
public function execute()
    {
        $output = $this->layoutFactory->create()
            ->createBlock('Fastly\Cdn\Block\Dashboard\Tab\Stats\Historic')
            ->toHtml();
        $resultRaw = $this->resultRawFactory->create();
        return $resultRaw->setContents($output);
    }
public function execute()
    {
        $output = $this->layoutFactory->create()
            ->createBlock('Fastly\Cdn\Block\Dashboard\Tab\Stats\Historic')
            ->toHtml();
        $resultRaw = $this->resultRawFactory->create();
        return $resultRaw->setContents($output);
    }
public function execute ( ) { $ output = $ this -> layoutFactory -> create ( ) -> createBlock ( 'Fastly\Cdn\Block\Dashboard\Tab\Stats\Historic' ) -> toHtml ( ) ; $ resultRaw = $ this -> resultRawFactory -> create ( ) ; return $ resultRaw -> setContents ( $ output ) ; }
Return historic stats

@return \Magento\Framework\Controller\Result\Raw
Return historic stats