public static function isUniqueVisitorsEnabled($periodLabel)
    {
        $generalSettings = Config::getInstance()->General;

        $settingName = "enable_processing_unique_visitors_$periodLabel";
        $result = !empty($generalSettings[$settingName]) && $generalSettings[$settingName] == 1;

        // check enable_processing_unique_visitors_year_and_range for backwards compatibility
        if (($periodLabel == 'year' || $periodLabel == 'range')
            && isset($generalSettings['enable_processing_unique_visitors_year_and_range'])
        ) {
            $result |= $generalSettings['enable_processing_unique_visitors_year_and_range'] == 1;
        }

        return $result;
    }