PSMR20 = Average FOB monthly price of SMR20 (US$ /ton)
TPNR = Total production of natural rubber (000 tons)
TCNR = Total consumption of natural rubber (000 tons)
STONR = World total stock of natural rubber (000 tons)
COP = Crude oil monthly price (US$/barrel)
EXM = Exchange rate for Malaysia RM to USD
TPPCT = Total production of passenger cars' tyres (000 units)
TPCVCT = Total production of commercial vehicle cars' tyres (000 units)
TPNRP = Total production of natural rubber products (000 tons)