function freqCount($arr, $el, $level = 0, &$return = []) {
    if (!isset($return[$level])) {
        $return[$level] = [$level, 0];
    }

    foreach ($arr as $value) {
        if (is_array($value)) {
            freqCount($value, $el, $level+1, $return);
        } else {
            if ($value == $el) {
                $return[$level][1]++;
            }
        }
    }

    return $return;
}