請人幫CHECK GAMMAR!!!!

In this proposal, i will address the issue of students bringing their mobiles phone to school with rationales.
I'd rewrite your 2nd paragraph as it's too repetitive - 'According to my research, 0.16% of students were caught carrying/using a mobile phone at school in 2001; 1.58% in 2002; 2.67% in 2003; 54.2% in 2004; and 7.5% in 2005. The chart here shows a continuous linear growth in the number of students with mbile phones. This might be due to the ease of obtaining a mobile phone in recent years.' (no need to state 'with their mobile phones' everytime. it's already mentioned)
The solution to this is that (cut this word out) to let the students to (cut) bring their mobiles to school with rationales. Bringing the (cut) mobiles (cut) phones to school is a convenient way of communication and it is useful in case of emergency. Also, their parents can trace (use 'track' for movements) the whereabouts of their children. Although bringing mobiles to school is useful in case of emergency, but the ring tone (change to 'ringing phones') are disturbing.
To be rationales ('rational'), schools should make some rules of bringing mobiles to school and set some (cut) penalties for the (cut) students who did ('failed to') follow the rules. Turn off the phone during lessons, assembly and exam period, they cannot use their mobiles in the classroom, special labs, library or exam hall. ('Phones should be turned off and not to be used during lessons, assemblies and in exam halls.')For the rule-breakers will receive warning letters or demerit point. ('Those who failed to comply will receive warning letters and merit points deducted')
Some words can be cut out and rephrased to make it sound more professional. Some grammatical problems also presented.
Hope that helps.