I’m using a custom table with a additional column, so I can’t use regular wp_query.
My code is working great except for the total number of post.
I want to display 5 results per page (which works great) but only display 20 post at total.

global $wpdb;

$items_per_page = 5;

only 5 posts per page

$page = isset( $_GET['cpage'] ) ? abs( (int) $_GET['cpage'] ) : 1;
$offset = ( $page * $items_per_page ) - $items_per_page;
$query = "SELECT post_id FROM $wpdb->postmeta WHERE country = 'fr'"; 
$total_query = "SELECT COUNT(1) FROM (${query}) AS combined_table";
$total = '20'; 
//$total = '$wpdb->get_var( $total_query )';

I tried to put 20. But if you put manually ‘5’ in your url, then
you see the other results.

$results = $wpdb->get_results( $query.' ORDER BY traffic DESC LIMIT '. $offset.', '. $items_per_page);

foreach ( $results as $result ) {
    echo get_the_title( $result->post_id );
}
echo paginate_links( array(
    'base' => add_query_arg( 'cpage', '%#%' ),
    'format' => '',
    'prev_text' => __('«'),
    'next_text' => __('»'),
    'total' => ceil($total / $items_per_page), 
    'current' => $page
));