I believe you are correct wraysburymum...... the NFER tests are standardised. If there is a higher number of children achieving a higher score then the bar for the 111 will probably be set higher...if the consortium exam was seen as harder than usual then the marks to achieve the '111' will be lower. Both exams for the Consortium and Slough Grammar are set by NFER but were different papers......the children are measured against the cohort taking the exam.
Not being absolutely sure of the 'workings' of the Slough system (oh the secrecy of it all)
I am willing to be corrected.