Burgers have been a top item ordered at U.S. restaurants for decades, but chicken sandwiches have come on strong over the last several years. There are more chicken sandwich restaurant concepts, and chicken sandwiches are appearing on more menus.

So, have burgers been knocked off their perch by chicken sandwiches? “No,” said The NPD Group, which tracks daily U.S. consumer use of restaurants and other foodservice outlets. Burgers still rule the roost and are the top sandwich ordered overall, it said.

By the numbers, the average times a customer purchased a burger at a restaurant over the 12-month period ending February 2019 was 14.7 times, while the purchase frequency of chicken sandwiches was 8.7, according to NPD’s receipt harvesting service Checkout, which tracks the same buyer's purchasing behaviors over time. Burgers also have the upper hand when it comes to menu importance or the percentage of all restaurant orders that include one. Burgers are included in 14.1% of all restaurant orders, and chicken sandwiches are included in 6.5% of orders.

Although chicken sandwiches are number two in the sandwich pecking order, they are gaining ground, NPD Group said. Chicken sandwich servings ordered in the year ending February 2019 were up 4% from same period year ago to 4 billion servings. Burger orders, on the other hand, were flat from a year ago, with 8.6 billion ordered.

“Both burgers and chicken sandwiches are winners for foodservice and restaurant operators. Both are popular with consumers, and both can be dressed up with different flavors and fixings to meet a variety of different tastes,” said David Portalatin, NPD food industry advisor and author of "Eating Patterns in America."