wp post view counter not work

it work only new post but alredy published post not work

// function to display number of posts.
function getPostViews($postID){
$count_key = 'post_views_count';
$count = get_post_meta($postID, $count_key, true);
if($count==''){
delete_post_meta($postID, $count_key);
add_post_meta($postID, $count_key, '0');
return "0";
}
return $count.'';
}

// function to count views.
function setPostViews($postID) {
$count_key = 'post_views_count';
$count = get_post_meta($postID, $count_key, true);
if($count==''){
$count = 0;
delete_post_meta($postID, $count_key);
add_post_meta($postID, $count_key, '0');
}else{
$count++;
update_post_meta($postID, $count_key, $count);
}
}

Code (JavaScript):

 

fix it