4.2 Energy usage 1000 GJ 1020.31 1059.51 4.3 External energy usage (3) 1000 GJ 249.56 292.44 4.4 Internal energy usage (4) 1000 GJ 770.75 767.07 5.0 Safety & Health 5.1 Frequency rate for Lost Time Accidents (5) Number 1.16 1.13 5.2 Incidence rate for Lost Time Accidents (6) Number 4.96 2.65 6.0 Wastewater 6.1 Volume discharged (7) 1000 cu.