如果未填充周数，则将0插入变量

For my admin page I created a graph which shows my registerd members per week for 2016 and 2015.

The Mysql query is working fine but when in a certain week no members has registerd the graph just moves one position to the left.

Mysql query

    SELECT WEEKOFYEAR( date) AS weekno, COUNT( 1 ) AS signup, 
           SUBDATE( date, INTERVAL WEEKDAY( date) DAY ) AS date_of_week
    FROM members
    WHERE YEAR( date) = '".$year."'
    GROUP BY WEEKOFYEAR( date);

What I (asume) need to do is check the array for missing weekno and if so fill the (new?) array with the missing weekno and add value 0 to signups.

foreach($oMember as $val) {
    $signups = $val[signups];
    $weekno = $val[weekno];
    if(empty($val)) { $val = '0'; }
}

This is what I tried but stil without any good working solution, also array search from Halil:

 array_search(strtolower($search), array_map('strtolower', $array));

Hope someone can help.

Best regards. Jan