i have bought and claimed PC for 2008 income tax and last year (2011) has buy another one. so has I reached the allowable time to claim (every 3 years)?

I have leave my PRUBSN education plan to lapse because have another plan. already declare tax today and suddenly receive also PRU annual statement later today (why they sent too late). I realized they paid my contribution using my investment money and that means I can get more tax relief if they send the statement earlier