What is the oldest age of a toddler starting to walk?

What is the oldest age  of a toddler starting to walk?

Within the framework of the Zurich longitudinal study, pediatricians conducted a detailed study of the development of 119 boys and 103 girls.

Researchers examined children seven times during the first two years of their lives and subsequently performed motor and intelligence tests with them every two to three years after schooling age.

Results show that children first sit between the ages of less than four months and thirteen months (average 6.5 months). They start walking between the ages of 8.5 months and 20 months (average 12 months). In other words, there is considerable variation.

Researchers found no association between the age at which children reached these motor milestones and their performance in intelligence and motor tests between the ages of seven and eighteen. In short, by the time they reach school age, children who start walking later than others are as well-coordinated and intelligent as those who got up early on their feet.