Please review this IELTS task 1

The graph exhibits the shares of internet users by various categorised groups of age in three years from 1998 to 2000.

Overall, the users within the working ages from 16 to 50 years occupied the absolute majority of the total users over the period. Meanwhile, the number of internet users less than 15 or over 50 years old were still very low, but tended to rise steadily in the latter years. In 1998, the young people (from 16 to 30) were the largest group who adopted internet services taking over 50% of the total users. Combining with the middle-age group, the percentage of internet users in both groups took a predominant place (approximately 90%) compared to the other ones.

With regard to the following years, the quantity of young and middle-age users gradually droped to less than 50% and 40%, respectively while there were a considerably increase of adolescents and ageing people who registered somewhat internet services. However, the market shares in these groups remained at a moderate value (less than 10% per each).