The failure rate on the citizenship test has been low until recently; in 2008, approximately 4% of the 145,000 test takers failed.
However, the failure rate for the new citizenship test is much higher. When it was first introduced on March 15, 2010, the failure rate rose to 30%. Later on, a reworked version of the test introduced on October 14, 2010 brought the national failure rate down to around 20%, but the rate was still significantly higher than that of the old test
https://www.thestar.com/news/canada/2010/11/29/massive_failure_rates_follow_new_tougher_canadian_citizenship_tests.html