was typically a bit volatile.
"We usually average February and March to get a true picture of what's actually happening," he told the BBC.
"If we look at February's 48% rise in exports and March's 15% fall in exports, we get a moving average of 16.7%, which is closer to where we've seen exports over the past two months."
But Mr Nash said Delta Economics was expecting a further slowdown going forward.
"In the second quarter, we'll look for an average of 9.9% year-on-year export growth and 11.7% import growth," he said.
"Trade will fall towards the back half of the year and we will look for average export growth in 2015 at 8.7% year-on-year, and import growth at 10.3% year-on-year.