During the middle months of the year the dollar closely tracked the official rate, with repeated triggerings of the convertibility undertaking and the purchase of a total of $ 51.5 billion worth of hong kong dollars by the hkma 在年中几个月内,港元汇率贴近联系汇率,兑换保证被多次触发,金管局合共买入总值515亿元的港元。