While the Wall St Crash of 1929 had little direct impact on the British stock market, the collapse of the American economy which it had foretold and the associated contraction of world trade seriously affected Britain in the early 1930s. Whereas British politicians had championed the concept of the free market when it was ascendant in the world economy, it gradually withdrew to adopting Tariff Reform as a measure of protectionism. In 1933 Sterling left the Gold Standard. By the early 1930s, the depression again signalled the economic problems the British economy faced. Unemployment soared during this period; from just over 10% in 1929 to more than 20% (or more than 3 million of the workforce) by early 1933. However, it had fallen to 13.9% by the start of 1936. While heavy industry sank to new lows, the consumer industry recovered by 1934 and production increased by 32% between 1933 and 1937. A good indication of the strong consumer market was the growth of retailers during the 1930s. Marks &amp; Spencer, for example, increased its turnover from £2.5 million in 1929 to over £25 million in 1939, necessitating the opening of dozens of new locations to serve the burgeoning demand in the suburbs.