public TSPetrol()
        {
            CentralPetrol cp = new CentralPetrol();

            cpCost   = cp.GetLatestPetrolPrice(1);
            StateTax = 20.15;
            VAT      = 15;
        }
        public ApPetrol()
        {
            CentralPetrol cp = new CentralPetrol();

            cpCost   = cp.GetLatestPetrolPrice(1);
            StateTax = 24.15;
            VAT      = 19;
        }