The number of stoppages across the UK peaked at 4,583 in 1979, when more than 29 million working days had been lost. In 1984, the year of the miners' strike, there were 1,221, resulting in the loss of more than 27 million working days. Stoppages then fell steadily throughout the rest of Thatcher's premiership; in 1990 there were 630 and fewer than 2 million working days lost, and they continued to fall thereafter. Thatcher's tenure also witnessed a sharp decline in trade union density, with the percentage of workers belonging to a trade union falling from 57.3% in 1979 to 49.5% in 1985. In 1979 up until Thatcher's final year in office, trade union membership also fell, from 13.5 million in 1979 to fewer than 10 million.