WASHINGTON — The National Restaurant Association’s Restaurant Performance Index stood at 101.4 in May, down 0.2% from 101.6 in April. It is the seventh consecutive month the index has been above 100.

“Despite a soft patch in the overall economy, restaurant operators reported positive same-store sales for the 12th consecutive month,” said Hudson Riehle, senior vice-president of the research and knowledge group for the N.R.A. “Looking forward, restaurant operators remain generally optimistic about sales growth in the months ahead, though they are somewhat less bullish about the direction of the economy.”

Restaurant operators reported positive same-store sales for the 12th consecutive month with 61% of operators reporting a same-store sales gain compared with the previous year, up from 57% who reported a sales gain in April. At the same time 28% of operators reported lower same-store sales, up from 25% who reported the same in April.

Restaurant operators had softer customer traffic in May with 42% of operators reporting higher customer traffic levels, down from 46% who reported higher traffic in April. In addition, 39% of operators reported lower customer traffic levels in May, up from 30% in April.

Operators are still mostly optimistic sales levels will improve in coming months with 48% of operators expecting to have higher sales in six months, down from 52% who said the same last month. In addition, 8% of restaurant operators expect their sales volume to be lower in six months than it was during the same period of the previous year, unchanged from last month.

Operators are also slightly less optimistic about the direction of the economy with 36% saying they expect conditions to improve in six months, up from 34% last month. Yet 19% of operators said they expect economic conditions to worsen in six months, up from 10% last month.