<?php

$str = 'Total%20M%C4%81ori%2C31.5%2C33.3%2C31.8%2C33%2C36.4%2C33.2%2C33.2';
$rawstr = rawurldecode($str);

var_dump(
    mb_detect_encoding($rawstr, ['UTF-8', 'ISO-8859-1', 'WINDOWS-1251']),
    mb_detect_encoding($rawstr, ['ISO-8859-1', 'WINDOWS-1251', 'UTF-8']),
    mb_detect_encoding($rawstr, ['WINDOWS-1251', 'UTF-8', 'ISO-8859-1']),
    mb_check_encoding($rawstr, 'ISO-8859-1'),
    mb_check_encoding($rawstr, 'UTF-8'),
    mb_check_encoding($rawstr, 'WINDOWS-1251'),
);