question: What did Liberia 's score and ranking on the 2010 Corruption Perceptions index represent ?
answer: a significant improvement since 2007
turker_answer: Liberia 's score and ranking on the 2010 Corruption Perceptions index represented a significant improvement since 2007 .
rule-based: Liberia 's score and ranking on the 2010 Corruption Perceptions index represented a significant improvement since 2007 .