More than half of all corporations in Canada have no women on their board, according to new research from Statistics Canada that includes the first data on private firms and government enterprises, alongside public companies.

The national statistical agency published new data on Tuesday on the gender make-up of corporate boards that covers all types of corporations. Overall, it found that 19.4% of all directors are female, based on data for 2016 that includes 12,762 corporations.

The study also reported that 56.8% of corporations have zero women on their board, 28.0% have one woman on the board and just 15.2% have more than one female director.

Government enterprises have the highest share of women on their boards at 28.8%, public companies rank second at 20.5% and private companies come last at 17.4%.

“Although the share of women on corporate boards in publicly traded corporations has been well documented, this release fills an important data gap, by providing the first estimates for private corporations, government business enterprises and public corporations,” StatsCan noted.

By sector, the study found that service industries, such as finance, are more likely to have women on their boards.

In particular, it said the finance sector ranks first with 22.5% female directors, whereas the construction and manufacturing sectors have the lowest representation, at 12.8% and 14.4%, respectively.

The study also found that only a small fraction of companies have at least three women on their board, which it noted represents “critical mass” according to the academic literature on the composition of boards that leads to improved boardroom dynamics and helps create a positive environment for innovation.

Only 5.5% of public companies have at least three women on their board, and it’s just 4.2% for private firms.