To explain the graph a bit more clearly, the X axis is months and years, while the Y axis is the volume of industrial activity as a percentage of the average monthly output of 2009 (which, it should be noted, was depressed as a result of the global financial crisis).

FORBES: Russian Industrial Production Increases by 4% over 1st Quarter 2011

Figures released earlier on Wednesday showing the biggest monthly fall in German manufacturing output since April, also weighed on markets.

BBC: Business

The NBER uses key monthly indicators of economic output, including employment, industrial production, real personal income, and wholesale and retail sales - to determine when economic growth has turned negative, rather than relying solely on two quarterly declines in GDP.

BBC: US recession 'began last year'

Industrial production in the euro area fell by 0.5% in April, surprising economists who had expected a further rise in output after the 0.5% monthly increase in March.

ECONOMIST: Overview

Scottish manufacturing output contracted modestly in January, marking the seventh consecutive monthly fall in production levels in the sector.

BBC: PMI survey: Scottish economy gains momentum