Question: How much was charity spending was expended for charitable activities in Haiti?
SPARQL:
 select sum(xsd:decimal(?amount)) as ?sum from <http://linkedspending.aksw.org/concern2012> { ?obs qb:dataSet ls:concern2012. ?obs lso:concern2012-Level1 <https://openspending.org/concern2012/Level1/expended>. ?obs lso:concern2012-Level3 <https://openspending.org/concern2012/Level3/charitable-activities>. ?obs lso:concern2012-Level4 <https://openspending.org/concern2012/Level4/haiti>. ?obs lso:concern2012-amount ?amount. }