Efforts to boost Maine tourism activity during the “shoulder season” months of May, September and October have not affected spending on lodging during those months, according to a new report.

Still, tourism officials in the state said there are other indicators not included in the report from the Maine Development Foundation that show tourist activity during the shoulder months is gaining ground on the perennial peak months of July and August.

Boosting revenue from lodging, meals, retail sales and activities in the off-season months is a top priority for the Maine Office of Tourism. It markets the state as a year-round destination by promoting its beaches, cuisine, shopping, parks, hunting, whale-watching, birding, fall foliage, skiing, snowmobiling and many other attractions.

“Lengthening the season could help businesses that cater to tourists sustain more consistent revenues throughout the year, and provide more reliable year-round job opportunities to hospitality workers,” says the foundation report, released Friday. “Bolstering the ‘shoulder season’ could also increase the overall amount of tourism that takes place in Maine, without overtaxing the already-congested (in some places) summer months.”

The Maine Development Foundation, a private organization that promotes economic growth in the state, examined Maine Revenue Services monthly data on lodging sales from January 2004 through December 2014. It found that while lodging sales have trended upward for both peak and shoulder months since the 2008 recession (August 2015 hit a record high of $184.2 million), the share of annual lodging revenue generated during the shoulder months has held steady at 27 percent to 28 percent. Meanwhile, revenue for the peak months of June, July and August also held steady at 52 percent to 54 percent of total annual revenue.

That would seem to indicate that efforts to boost tourism activity specifically during off-peak months have been ineffective.

“Although tourists visiting Maine spend money on goods and services other than accommodations – and many day trippers visit the state without staying at a hotel or motel – lodging sales are a reasonable proxy for the number of tourists visiting Maine,” says the report, authored by University of Maine economics professor Todd Gabe.

However, two top officials in Maine’s tourism industry took issue with that conclusion. Carolann Ouellette, director of the Maine Office of Tourism, and Greg Dugal, president and CEO of the Maine Innkeepers Association, said lodging sales data alone aren’t sufficient to gauge what is happening with tourism in any given month.

Ouellette said her office tracks several indicators including monthly visitation – the total number of visits to Maine each month. Those data show a nearly 13 percent increase in visitation from fall 2014 to fall 2015, compared with a 5 percent increase for the summer months.

In other words, visitation data show that the shoulder months are gaining ground in terms of tourism activity, she said.

“(Lodging sales data) doesn’t tell the whole story,” Ouellette said. “There’s so many other variables.”

Dugal said a likely reason why the monthly distribution of lodging sales revenue didn’t change is that room rate increases drove revenue higher in the peak months, while occupancy increases drove it higher in the shoulder months. In other words, there was a bigger increase in the number of people who stayed in hotels and inns during the shoulder months, but a smaller increase in the amount they paid for a room.

“It’s not just a function of occupancy,” Dugal said. “It’s a function of rate, too.”

Gabe, the report’s author, said it isn’t necessarily a good or bad thing that the share of lodging sales coming from shoulder months has barely changed. But the report’s other major finding – that sales revenue for all six busiest months of the year has increased regularly since 2009 – is very good news. Overall lodging sales revenue reached a record high of $849.1 million in 2015, up 6 percent from the previous year, according to Maine Revenue Services data.

“The trend is upward,” he said. “All hospitality sales are growing over time.”