lib/SteamCondenser/Community/GameAchievement.php
public static function getGlobalPercentages($appId) {
        $params = ['gameid' => $appId];
        $data = WebApi::getJSONObject('ISteamUserStats', 'GetGlobalAchievementPercentagesForApp', 2, $params);

        $percentages = [];
        foreach($data->achievementpercentages->achievements as $achievementData) {
            $percentages[$achievementData->name] = (float) $achievementData->percent;
        }

        return $percentages;
    }
public static function getGlobalPercentages($appId) {
        $params = ['gameid' => $appId];
        $data = WebApi::getJSONObject('ISteamUserStats', 'GetGlobalAchievementPercentagesForApp', 2, $params);

        $percentages = [];
        foreach($data->achievementpercentages->achievements as $achievementData) {
            $percentages[$achievementData->name] = (float) $achievementData->percent;
        }

        return $percentages;
    }
Loads the global unlock percentages of all achievements for the given
game

@param int $appId The unique Steam Application ID of the game (e.g.
<var>440</var> for Team Fortress 2). See
http://developer.valvesoftware.com/wiki/Steam_Application_IDs for
all application IDs
@return array The symbolic achievement names with the corresponding
global unlock percentages
@throws \SteamCondenser\Exceptions\WebApiException if a request to
Steam's Web API fails