Can someone answer following questions regarding -- Jeevan Surabhi Policy [LIC] ??

I have taken a 15yr. Jeevan surabhi policy for Rs.50000/- under Table no. 106-15-12.this commenced in 1997 and will complete by 2012.this consists of 12 installments of Rs.5336/- per yr.LIC makes part refund on 4th , 8th,12th yr. and after the 15th yr. bonus etc is paid. so far i have got 2 refunds worth Rs.15000/- each.can someone tell me how much will be the 3rd refund and what lump sum amount i am likely to receive in form of bonus plus other benefits ??