The national parks brought in nearly $36 billion for the economy last year, the highest amount in at least six years, Interior Secretary Ryan Zinke said Wednesday.

The annual report touts the economic value the parks generate for their surrounding communities and the nation. Zinke had recently sought to double and triple entrance fees at parks to pay for maintenance, but pared back the plan after public outcry opposing the rate hikes.

“This report illustrates the incredible economic value of our national parks, and further shows the value in President Trump's plan to rebuild park infrastructure,” Zinke said.

The report showed visitor spending in communities near national parks generated $35.8 billion in benefits to the nation’s economy, which the Interior Department said was almost a $1 billion increase from 2016.

The National Parks did do well over the past five years, with 2017 being one of the highest for economic output in past two years. Yet, the numbers cited by the Interior Department don't seem to add up to support a near $1 billion increase from 2016.

In the past year of the Obama administration — and the 100th anniversary of the National Park Service — the parks had more visitors than in 2017, higher visitor spending, and more jobs supported than in the first year of the Trump administration.

Yet, in 2017 the total aggregated economic benefit from parks equaled $35.8 billion, while in 2016 the parks only raised $34.9 billion.

In 2017, the lodging sector saw the biggest direct contributions with $5.5 billion in economic output and 49,000 jobs, while the restaurant sector generated the second-greatest activity of $3.7 billion for local economies and 60,500 jobs.

"The variation in estimates is due to a data update to the system used for the estimates," said a National Park Service spokesman. Basically, a change added to the software the park service uses estimated an increase in output per worker from a previous data set, which "increased the total estimated economic output while estimating slightly lower numbers for earnings and jobs."

Multipliers differ between the 2013 and updated 2015 software data sets used for the 2016 and 2017 visitor spending analyses, according to the agency.

"Overall, jobs and labor income multipliers are relatively smaller in the 2015 IMPLAN data set compared to the 2013 IMPLAN data set; this reflects an increase in output per worker and explains why economic output estimates increased for 2017 while earnings and jobs decreased," according to the park service.

• This article has been updated to add the park service's explanation of the data.