Factory sector activity in the US reported its best performance in over five years in January, boosting hopes of a growth in overall economic output. The data, released by private research group the Institute for Supply Management (ISM), provides further evidence that the US economy is continuing to emerge from recession. The ISM said its index of manufacturing activity, also known as the purchasing managers index, moved to 58.4 in JanuaryÔÇöthe best reading since August 2004. The reading was 54.9 in December and 53.7 in November. Readings over 50 indicate growth.