Export volumes are estimated to decrease from 5.9 per cent in 2011 to 0.5 per cent in 2012. Domestic supply constraints including electricity rationing in manufacturing and disruptions to mining output have exacerbated the pressure on exports, from weaker global demand. The weaker rand has provided little support for manufacturing export growth, which remains subdued in the current economic environment. The National Treasury forecast a significant improvement in export performance, averaging 3.5 per cent in 2013, increasing to 6.5 per cent in 2015. The improvement in total export growth over the medium term assumes that mining production stabilises, external demand strengthens and trade with emerging and African economies expands. The current account deficit is projected to moderate from 5.9 per cent in 2012 to 5.5 per cent of GDP in 2015.