 An analysis of the GCSE awards to pupils achieving the average YELLIS ability test score of 45, between 1996–2006, identified a general increase in awards over the 10 years, ranging from 0.2 (Science) to 0.8 (Maths) of a GCSE grade.It has also been suggested that the incorporation of GCSE awards into school league tables, and the setting of School level targets, at above national average levels of attainment, may be a driver of GCSE grade inflation.At the time of introduction the E grade was intended to equivalent to the CSE grade 4, and so obtainable by a candidate of average/median ability; Sir Keith Joseph set Schools a target to have 90% of their pupil obtain a minimum of a grade F (which was the 'average' grade achieved in 1988), the target was achieved nationally in summer of 2005.