THE US economy grew at an annualised pace of 2.5 per cent in the second quarter of the year, the American government revealed. That was more than double the pace recorded in the previous three months, and above estimates of 2.2 per cent. The rise, helped by an increase in exports, is a further sign that the economy may be getting back on track. The government had originally estimated that GDP grew at a 1.7 per cent rate in the second quarter. The revised non-annualised quarter on quarter figure was 0.6 per cent, up from an initial 0.4 per cent estimate.