Infation within 2%???

I was watching 8TV news and our Bank Negara Governor Dr Zeti mentioned that Malaysia inflation rate will maintain within 2% and still within control. Sometime I am really wondering how do they compute the inflation rate.. In view that almost everything has increase for more than 5-10%. Some of the daily comsume item even increase by 30-50%. But our government still can easily say that our inflation rate is still low.. can anyone tell me why??