While Canadians continue to use registered retirement savings plans for retirement planning, knowledge about RRSPs has declined over the past five years, according to a new survey by BMO Global Asset Management.

It found 56 per cent of respondents know how much they can contribute to the account, a six per cent decrease since 2016. In addition, 47 per cent are aware of what investments are eligible to be held in RRSPs, a five per cent decrease since 2016.

Read: Canadians still not knowledgeable about RRSPs, TFSAs: survey

While more than half (56 per cent) of RRSP investors are aware that mutual funds are eligible for RRSPs, that knowledge has decreased by 15 per cent since 2016. And fewer than half of Canadians are aware that RRSPs can hold cash (47 per cent) and exchange-traded funds (45 per cent).

The survey also identified a gender gap in approaches to and knowledge about retirement planning. It found women are 12 per cent less likely to have an RRSP compared to men and are 17 per cent less likely to know how to contribute and how much can be contributed to an RRSP compared to men.

In addition, only 36 per cent of women are aware of which investments are eligible in an RRSP, compared to 59 per cent of men. And women are 20 per cent less confident than men that they will have enough to retire as planned.

Read: RRSP holdings on the rise, driven by millennial savers: study