Here is my xml

Code:
<dealer id="3691">
  <name>Bob's Truck</name>
  <remote_customer_id>ABC123</remote_customer_id>
  <listing id="197083">
    <stock_number>18005</stock_number>
    <industry>Agriculture</industry>
    <type>Hay/Forage Equip</type>
    <subtype>Round Baler</subtype>
    <make>New Holland</make>
    <model>BR750</model>
    <attributes>
      <attribute id="119" type="Option" name="Listing Type">Used</attribute>
      <attribute id="36" type="Integer" name="Year">2007</attribute>
      <attribute id="35" type="Price" name="Price" currency="NZD" gst="15" gst_value="ex-GST">18900</attribute>
      <attribute id="19" type="Paragraph" name="Description">New Holland BR750 done 35000 bales, tidy baler, crop cutter, hyd reverser, brakes, runs very well.</attribute>
    </attributes>
  </listing>
  <listing id="298499">
		<stock_number>XT4924</stock_number>
		<industry>Transport</industry>
		<type>Trailer</type>
		<subtype>Tipper-trailer</subtype>
		<make>Lusty</make>
		<model>B/D Combination</model>
		<attributes>
			<attribute name="Item Condition" id="236" type="Option">New</attribute>
			<attribute name="Year" id="36" type="Integer">2007</attribute>
			<attribute name="Description" id="19" type="Paragraph">This trailer is
				brand new.
				It is floor stock at our dealership.
				Price is negotiatble.</attribute>
			<attribute name="Susp Options" id="63" type="Option">Air Bag</attribute>
			<attribute name="Hubmeter" id="243" type="Integer" uom="KM">231</attribute>
			<attribute name="Price" id="35" type="Price" currency="AUD" gst="10" gst_value="ex-GST" price_type="Drive Away no more to Pay">202141.82</attribute>
		</attributes>
	</listing>
</dealer>
How can I sort the 2 listings by Year or Price? Cheers.