Add DESC Number Before Title Post

functions.php:
===============
/*
---------------------
Nomor DESC
---------------------
*/

function get_post_position_in_reverse()
{
    // Invoke the global $wp_query object
    global $wp_query;

    // Make sure that we are actually inside the loop, if not, bail
    if ( !in_the_loop() )
        return false;

    //Setup our variables we will be using
    // Get the current page we are on
    if ( get_query_var( 'paged' ) ) {
        $current_page = get_query_var( 'paged' );
    } elseif ( get_query_var( 'page' ) ) {
        $current_page = get_query_var( 'page' );
    } else {
        $current_page = 1;
    }

    // Get the current post's position plus 1 as post counter starts at 0
    $post_position = $wp_query->current_post + 1;
    // Get the total amount of posts in the query
    $total_posts   = $wp_query->found_posts;
    // Get the amount of posts_per_page from backend
    $ppp           = get_option( 'posts_per_page' );

    /**
     * Now that we have everything set up, we need to do the maths
     *
     * If we have 20 posts across 4 pages with 6 posts per page, we will have
     * 6 posts on pages 1,2 and 3 and only 2 posts on page 4. Our post numbers
     * will be as follow, the first post on page one will be 20 and the last
     * post on page 4 will be 1
     */
    $number = $total_posts - ( ( $current_page * $ppp ) - ( $ppp - $post_position ) ) + 1;

    return number_format_i18n( $number );
}

index.php loop:
---------------
<?php echo get_post_position_in_reverse(); ?>