GRADE A office rents in the core Central and Admiralty areas fell by an average of 1.3 per cent last month, to $87.15 per net square foot, according to figures released by City Property Consultants. But, overall, rents in these core areas rose 36.5 per cent last year, from $70.08 per sq ft in January to a peak of $89.68 in September. Rents declined steadily from then on to just over $87 last month. Vacancy rates in Central and Admiralty ranged from a low of one per cent in January to December's 2.6 per cent. In Wan Chai and Causeway Bay, City Property Consultant figures show average rents dropped by a slim 1.6 per cent to $59.33 per sq ft by the end of the year, up 33.4 per cent overall.