You need to display the list of cars in the code snippet below in a column format, with a counter column for each row. Which XPath function do you use for the counter?

<cars>
    <car><make>Cadillac</make> <model>Escalade</model> <year>2007</year></car>
    <car><make>Ford</make> <model>Mustang</model> <year>1968</year></car>
    <car><make>Mercedes</make> <model>C-Class</model> <year>1999</year></car>
</cars>