Total coal stocks with the thermal power stations came down to 9.6 million tonnes on March 3, 2003 from 11 million tonnes on October 1, 2002.
The time difference is over 5 months
( z1 differ :ARG3 ( z2 time ) :quant ( z3 over :op ( z4 temporal-quantity :quant 5 :unit ( z5 month ) ) ) )