The average age of a couple was 29 years. After their 1st and 2nd children (twins) were born, the average age of the family became 16 years. The average age of the family just after 3rd child was born was 15.2 years. The average age of the family after the 4th child was born was \(17\frac{2}{3}\) years. The current average age of the family is \(20\frac{2}{3}\) years. What is the current age of the twin children?