Google Docs Java Script find and sum up all values

So, i'm trying to get all 'skillpoints' values from the api file(part of it below):

<eveapi version="2">
<currentTime>2016-08-07 00:13:34</currentTime>
<result>
<freeSkillPoints>0</freeSkillPoints>
<rowset name="skills" key="typeID" columns="typeID,typeName,skillpoints,level,published">
<row typeID="2495" typeName="Interplanetary Consolidation" skillpoints="32120" level="3" published="1"/>
<row typeID="2505" typeName="Command Center Upgrades" skillpoints="32000" level="3" published="1"/>

and sum them up, how can i do it?