Please review my IELTS writing task 1. Thank you very much.

The given line chart compares four means of communication used by teenagers in one US state in a three-period from 2006 to 2009.
Overall, while the general trend for teenagers’ methods of communication was upward, the opposite was true for email. Also, texting messages shows the most dramatic rise in the later years.
The percentage of text messaging gradually increased in the first two years, reaching under 40% in Feb 2008. After that, the figures show a sudden increase with a jump of 15% in just one year and become the most popular means of interaction among US youngsters. Meanwhile, the use of cell phone calls remains stable, with a moderate increase from 35% to 38% in the period shown. In sharp contrast, the figures for face-to-face communication show a fluctuation between 30% and 40%, peaking at 40% in 2007, then fell back to approximately 35% in Sep 2009. After a period of stability from 2006 to 2008, there was a drop in the proportion of young adults using emailing as their way of communication, reaching nearly 10% in 2009.