public function getTotalIndividuals() {
	    if(!$this->is_setup) return 0;
	    return Database::prepare(
	        'SELECT COUNT(*) FROM `##individuals`' .
	        ' WHERE i_file = :tree_id')
	        ->execute(array('tree_id' => $this->tree->getTreeId()))
	        ->fetchOne() ?: 0;
	}