They show Waitrose and Aldi grew by 12.5 per cent and 30.8 per cent respectively over the same period a year ago. Lidl and Iceland also showed strong growth.
Sainsbury's was the winner among the "big four" with 6.9 per cent growth, well ahead of the overall sector's growth of 3.9 per cent and continuing a rising trend since 2004. Tesco and Morrisons slipped back slightly.
"Austerity and provenance have been the key factors," said the market research agency, pointing out that Waitrose and Sainsbury's largely avoided adverse media coverage of the horsemeat scandal.
In Ireland, meanwhile, Aldi and Lidl together now account for one-eighth of the grocery market.