The country's industrial production declined 3.5 per cent in March 2012, mainly on account of contraction in manufacturing and mining output. Growth in factory output, as measured by the Index of Industrial Production, had stood at 9.4 per cent in March last year. Output of the manufacturing sector, which constitutes over 75 per cent of the index, contracted 4.4 per cent in March. Mining output declined 1.3 per cent during the month.And growth in industrial production slowed to 2.8 per cent in the whole of 2011-12, against 8.2 per cent growth in the previous fiscal, as per the latest government data released today.