More than 15 census records are available for the LeDuc family, from both 1901 and 1911.
Sample 1901 Cornwall & Stormont census records about the LeDuc family available from Ancestry.ca:
A LeDuc family household of at least 9 members residing in the district of Cornwall & Stormont was recorded in 1901. The head of household, Alexander LeDuc, was born in Ontario in 1868. He identified his heritage as French. By 1901, at the age of 32, he had an occupation that was recorded as "Laborer". Alexander's wife was Delamon LeDuc, who was 31 years old. Delamon was born in Ontario in 1869. She also identified her heritage as French. Alexander and Delamon had 7 children, 4 boys and 3 girls. In 1888 their eldest child, a boy named Alfred, was born. Two years later, in 1890, when Alexander was 22 years old and Delamon was 21 years old their second child, this time a daughter, who was named Mary, was born. Then, in 1891, with their two children ages 3 years and 1 year, their third child, Oyesias, was born. In 1901 another daughter, their fourth child and second girl, Seyerian, was born. With four other children in the household, their fifth child and third girl, Olive, was born in 1894. She was followed by 2 more children: their son Ulrie, born in 1896; and their son Ernest, born in 1899. Thus, at the time of the 1901 census, this LeDuc family household was filled with 7 children whose ages were 1, 4, 6, 8, 9, 10, and 12 years.