global $wpdb;
$winningyear = $wpdb->get_results("SELECT value<, COUNT(*) as win_year FROM wp_bp_xprofile_data WHERE field_id =6 GROUP BY value ORDER BY COUNT(*) DESC LIMIT 1", ARRAY_A);

foreach ($winningyear as $winners)
{
echo "<h3><center>The Alumni year with the most registered users is:<B><font color=red> $winners[value]</Font> </B> with $winners[win_year] members.</h3></center>";
}