If you think you'll want to have a job/account/credit card with HSBC in the future, the answer is "0". Delinquencies stay on the internal records, even if it no longer is recorded with Transunion. Transunion's FAQ is a bit vague, but I suspect it falls off after 7 years.

Your bigger problem may be if you owe taxes to IRD.

http://www.transunion.hk/personal/cr...e/faqs_en.html
Q How long can TransUnion retain the relevant individual credit information?
A In accordance with the Code of Practice on Consumer Credit Data issued by the Office of the Privacy Commissioner for Personal Data, Hong Kong, retention time limits are as follows:
TransUnion can retain current credit card and personal loan records for credit reference purposes.
TransUnion can retain normal closed credit card and personal loan records up to five years from the date of account termination.
TransUnion can retain delinquent records for up to a five-year period from the date of full settlement, or five years from the discharge of bankruptcy, as notified by the individual in accordance with the Code of Practice on Consumer Credit Data issued by the Office of the Privacy Commissioner for Personal Data, Hong Kong (whichever occurs first).
TransUnion can retain records for filed bankruptcy petitions for eight years and other public records for seven years from the dates of legal proceedings.
TransUnion can retain enquiries made by its members for two years from the dates of such enquiries.
TransUnion will promptly delete terminated accounts in our database, upon receiving appropriate notification from members, when the amount due has not been in any payment default for more than 60 days within a five-year period.