Statistics Canada says the response rate for the 2016 census was its highest yet, but there will always be Canadians who refuse to participate.

For the 2016 census, 98.4 per cent of Canadians filled out either the long- or short-form census. Most of the remaining 1.6 per cent couldn't be tracked down or didn't provide enough information to be counted properly.

Statistics Canada identified 347 people unwilling to fill out the forms.

"At some point over the next couple of months we will decide if any cases will be referred to the Public Prosecution Service of Canada," said Statistics Canada spokesman Marc Hamel.

Census requirements became a hot-button issue in 2010 when the Harper government changed the rules for the long-form census, making it voluntary instead of mandatory.

As a result, the response rate for the long-form census dropped to 68 per cent in 2011, down from 93 per cent in 2006. The drop was widely viewed as diminishing the value of the statistical information.

Penalties for not completing census

Shortly after forming government the Liberals reinstated the long-form census as mandatory, meaning those who refuse could be criminally charged with penalties up to $500 in fines or three months in jail.

The short-form census, which is the one most people get, has always been mandatory and there have always been people who refuse to fill it out.

People's motivations for not completing the census forms vary.

"They can never make it 100 per cent secure," said Philip Marsh of McBride, B.C.

Marsh refused to to fill out the short-form census in 2011 and was charged with breaching the Statistics Canada Act. He argued the prosecution was arbitrary and that he shouldn't be compelled to reveal details about his personal life to the federal government.

"They don't need to be storing my personal information about what my religion is or who my friends are. They need to know that I'm an upstanding citizen and I pay my taxes," he said.

Toronto Audrey Tobias court

Activist Audrey Tobias objected to Lockheed Martin's involvement with processing the census in 2011. She died in December 2016. (Chris Young/The Canadian Press)

The judge ruled against Marsh.

Others have refused to fill out the census because Lockheed Martin helped Statistics Canada process the data. They considered themselves to be conscientious objectors to the weapons contractor's involvement.

But that's changed.

Court action

Statistics Canada confirmed to CBC News that Lockheed Martin is no longer involved with the census.

"For the 2016 Census … all systems were developed in-house," it said in an email. 

Of the 347 people who have been identified as unwilling to fill out the latest census, Statistics Canada says it's still deciding who they'll pursue through the courts.

In 2011, Statistics Canada referred 54 cases to Canada's Public Prosecution Service.

In 2006, that number was around 60.