get_xpath returns a list (see the docs), so in your case when you write $bay = $_->get_xpath('bay'), $bay, gets assigned the number of elements in the list, presumably 1.

I believe what you want is $bay= $_->first_child( 'bay');. You can also use $bay = $_->get_xpath('bay', 0), but I believe it is much less clear than simply using first_child.