University Admission Handbook published by University Grants Commission contains Z-score table.
This table gives Minimum Z score cut off values for selection of various University courses in each district. 2017-2018 University handbook contains Z score values for 2017 GCE A/L Examination.
Download Z Score Table
2017 A/L Z -Scores - Minimum "Z" Scores for selection to various Courses of Study of Universities, in respect of each district for GCE (A/L) Examination 2017
Download Z-score table for 2017 A/L
2016 A/L Z-score cut off marks
2015 A/L Z Score cut off marks
If you need to check whether you are eligible to enter into Universities based on A/L examination read these posts also.
Z Scores Cut off marks for University admissions 2016 based on 2015 A/L results
District and Merit quotas: How to check your University, Faculty based on Island Rank IR and District Rank DR?