MPS was probably between 63-65% so you could have got between 51-70 in every subject scoring 62% in each subject and failed (Band 10), however you could also have gotten all subject in the range of 51-70 and scored 63% in each subject and passed.
For L1 with 240 questions there tends to be 8-11 between each failing band, therefore as a Band 8 failure you were a maximum of 32 questions correct from passing (13%) and a minimum of 23 questions from passing (10%). Therefore you score was most likely between 50% and 55%