One morning in May, cleaning worker Lau Chung dragged herself to the head office of Hong Kong’s Mandatory Provident Fund (MPF) Schemes Authority in Kwai Chung.Turning 65, the age that allows her to withdraw all her MPF cash, she wanted to find out how many pension accounts she had, and how much in savings, after working about 20 years as a cleaner.She was worried because she knew 2018 was a bad year for workers in terms of their MPF. The compulsory scheme reported a return of minus 8.21 per…