WP Core contributors count

<?php
include 'wp-load.php';

$wp_version = 4.8;

function get_credits( $wp_version, $locale = 'en_US' ) {
    $response = wp_remote_get( "http://api.wordpress.org/core/credits/1.1/?version=$wp_version&locale=$locale" );

    if ( is_wp_error( $response ) || 200 != wp_remote_retrieve_response_code( $response ) ) {
        return false;
    }

    $results = json_decode( wp_remote_retrieve_body( $response ), true );

    return $results;
}

$results = get_credits( $wp_version );

$groups = array();
foreach ( array( 'core-developers', 'contributing-developers', 'recent-rockstars', 'props' ) as $group ) {
    if ( isset( $results['groups'][ $group ]['data'] ) ) {
        $groups[] = count( $results['groups'][ $group ]['data'] );
    }
}

echo 'Contributors: ' . array_sum( $groups ) . '<br />';

$latest_release_props = $results['groups']['props']['data'];

$props = array();
for ( $version = 3.2; $version < $wp_version - 0.1; $version += 0.1 )  {
    $results = get_credits( number_format( $version, 1 ) );
    $props += $results['groups']['props']['data'];
}

$new_contributors = array_diff( $latest_release_props, $props );

echo 'New contributors: ' . count( $new_contributors ) . '<br />';