'post_days' returns wrong number when user has never made a post

I have my post count filtered to only count Forum entries. Many new users do not have forum posts. Therefore, when I am displaying the count for 'post_days', I am getting a very large number do to the fact that _user_stats_last_post($user) is equaled to 0 in case 'post_days' in function user_stats_get_stats().

This is how I solved the issue:

case 'post_days':
    if (_user_stats_last_post($user) == 0) {
        return 'n/a';
    } else {
        return floor((time() - _user_stats_last_post($user)) / 86400);
    }