CSAT was introduced in the year 2011 as a part of the Civil Services Exam (Preliminary) Examination in order to test the analytical skills, reasoning ability and aptitude of a candidate. From 2011-2014, the total marks of both GS Paper-1 (General Studies Paper) and GS Paper-2 (CSAT paper) were considered for calculating the UPSC CSE prelims ranking (to qualify for the mains examination). However, in 2015 the CSAT was made a qualifying paper. Only the marks of GS Paper 1 will be counted for calculating the Prelims ranking. However, candidates have to score a minimum of 33% i.e. 66 marks out of the 200 allotted for the GS Paper 2 paper (CSAT paper) in order to clear the Civil Services Preliminary Examination.