You may not operate a vehicle unless all child passengers FOUR YEARS OF AGE AND UNDER are properly restrained with an appropriate safety device.
Traffic law requires that children four years and below must be properly restrained in the vehicle using appropriate devices such as car seats.
Children older than four years have to use the safety belt when they are inside the car.
Their years fly by quicker maybe.
it's a summary of the number of individuals of each age in the population. Age structure is useful in understanding and predicting population growth. An understanding of population age structure is critically important to industries that harvest living organisms.
hope that i helped :)