The number of kindergartners over the age of 5 has more than tripled from 5.4% in 1970 to 17% in 2009 according to parents.com. I suspect in Alberta that number could be higher because of the late cutoff date.
Finland, a country the size of Minnesota, beats the U.S. in math, reading and science, even though Finnish children don't start school until age 7.
Despite the late start, the vast majority arrive with solid reading and math skills. By age 15, Finnish students outperform all but a few countries on international assessments.
From:
http://www.npr.org/2014/03/08/287255...tarts-at-age-7