OTTAWA -- Statistics Canada will offer a detailed look Wednesday at the size of the gap between the country's top income earners and those toiling at the bottom -- a chasm that appears to be narrowing but remains far too wide for many to easily cross.

The income data, collected as part of last year's census, will offer an important signpost for the Trudeau government, which is looking for validation of its efforts to date to help reduce inequality and lend moral support to those in the lower income brackets.

The numbers are expected to show a 10 per cent increase in median incomes for families and single people over the last decade, suggesting a medium-term trend of positive economic news.

More broadly, however, the gulf between rich and poor in Canada remains a wide one.

The gap between the poverty line and the "one per cent" was at its widest in recent history during the 1980s and 1990s, when those at the top earned about 14 times than the average Canadian. That gap did narrow somewhat over the past decade; research shows the very wealthy now earn about 10 times more than the average worker.

In 2015, the top 10 per cent of earners pulled in $153,600 in wages, or "market income" -- about three times the median market income of $52,700, and roughly the total of the median incomes for the bottom 60 per cent of Canadians.

"There's less confidence in social mobility," said Aaron Wudrick, federal director of the Canadian Taxpayers Federation.

"There's an increasing sense that the rules are rigged and the deck is stacked."

That same sentiment helped propel Donald Trump to the White House and helped drive Great Britain out of the European Union. Prime Minister Justin Trudeau has hinted that Liberal social policy is designed in part to counter it in Canada.

The income data is the latest in a year-long series of data dumps from Statistics Canada as it paints the country's most recent five-year census portrait. The first broad strokes began in February with population estimates, followed by details about age and gender, linguistic diversity and evolving family dynamics.

Details about trends in immigration, Indigenous Peoples, education and labour are due later this fall, which is when Statistics Canada will draw a more direct connection between various population segments and income levels.

This week's release is based entirely on tax data from the Canada Revenue Agency, a sign of things to come. The idea is to one day use a variety of similar administrative data sources to build a digital portrait, all but eliminating the need to fill out a questionnaire.

Statistics Canada already makes tax filer data publicly available, which provides a fairly good idea of what the agency is likely to reveal Wednesday.

Doug Norris, chief demographer at Environics Analytics, said the median income of families and unattached individuals was $63,400 in 2015, an increase of about 10 per cent since 2005, once adjusted for inflation.

The changes in income reflect the shifting structure of the family dynamic: Among other things, Canadians are staying in school, living at home longer and delaying marriage and kids to keep their incomes on an upward trajectory.

Norris said the data will likely show women's incomes increasing by about 18 per cent compared to a five per cent jump for men, with more women entering the labour force and male workers reeling from the 2009 recession.

There's also likely to be signs of income gains for lone-parent households -- evidence that the traditional image of the single parent as a mother under age 25 with limited education and limited support is slowing being eroded.

"That's not the typical profile of the single mother anymore," said Nora Spinks, CEO of the Vanier Institute of the Family, pointing to previous census data showing a rise in the number of women over 40 leading lone-parent homes.

Those older women tend to be better off financially because they are deeper in their careers, Spinks said, adding that fathers who are not partnered with mothers are more likely to be paying child support or contributing to household finances either directly with cash or indirectly through in-kind help.

The gender wage gap still remains -- Statistics Canada will reveal Wednesday how wide it was last year.

The biggest income gains provincially over the past five years are mostly likely to be in Alberta, Saskatchewan and Newfoundland and Labrador, the result of a boom in commodity prices that began to fade about three years ago.

The Liberal government's first budget offered extended employment insurance benefits to those hard-hit regions, anticipating costs of $827.4 million between April 2016 and March 2019.

As of early July, however, government coffers had doled out about $1.3 billion in additional benefits for some 317,261 claimants.

"This story (suggests) places like Newfoundland look pretty good," said Norris, "but in reality today I'm not sure they look too good."