UK commercial real estate returns fell by a record amount in December, according to Investment Property Databank’s (IPD) Monthly Index.

The total return on investments, which combines rental income and changes in property values, fell 3.7% in December. This makes it the worst performance since the index began in December 1986.

Annual all-property total returns fell to -5.5% which was the lowest since July 1991. This followed three years of returns of at least 18% as demand for commercial real estate drove building values higher. Retail properties were the worst performers and incurred a loss of about 7.6% last year.

Offices in London’s West End district were the only profitable investments in Britain’s commercial property market last year, returning 2.8% although offices throughout the rest of the UK were the worst-performing segment in December, delivering a loss of 4.7%.

In November and December, the biggest declines in property values were for office buildings in the City of London which fell more than 4% in each month. Industrial properties such as logistics centers and plants returned a negative 3% last month.