Data related to explosive and blasthole are given below. Assuming 1 kcal to be 4.2 kJ, the power of explosive in GW in the blasthole (round off to one decimal place) is ______.

• Diameter of the borehole: $200\ \text{mm}$
• Charge length: $8\ \text{m}$
• Density of ANFO: $0.8\ \text{g/cc}$
• Heat of explosion: $912\ \text{cal/g}$
• VOD: $4500\ \text{m/s}$
• Initiation: Bottom