The gauge of optimism at U.S. restaurants is pointing up.

The Washington, D.C.-based National Restaurant Association reported May 31 that its Restaurant Performance Index reached a 10-month high in April. The composite index, tracking the health and optimism of U.S. restaurant operators, scored 101 in April, up 0.4% from March, according to a news release from the NRA. The April index represents the third time in the last four months that the index topped the 100 level, according to the release.

“Growth in the Restaurant Performance Index was due largely to restaurant operators’ healthier outlook for the business environment in the coming months,” Hudson Riehle, senior vice president of the Research and Knowledge Group for the NRA, said in the release. “In particular, there was a dropoff in the proportion of operators who expect conditions to worsen in the months ahead, which suggests a broadening of the perspective that the expansion is firmly entrenched.”

Compared with April 2012, 49% restaurant operators surveyed in April this year reported same-store sales gains, while 33% reported a drop in same-store sales.

On the other hand, 40% of restaurant operators reported a net decline in traffic compared with a year ago; 36% reported higher traffic levels compared with a year ago.

The April index showed 41% of restaurant operators expect to have higher sales in the next six months; only 10% restaurant operators expect their sales to be lower then compared with year-ago levels, according to the release.

An index measuring the six-month outlook was at its highest level in 11 months.