From about 1978 time frame of 1 carrier, 3 guided missile destroyers, 3 destroyers, 6 frigates, and 6 submarines, the RAN has built up to 6 guided missile frigates, 8 frigates, and 6 submarines. Upcoming the fleet will comprise 2 landing helicopter docks, 3 or 4 guided missile destroyers, 8 frigates, and 6 to 8 submarines. If anything, the fleet has increased in numbers slowly. In Europe, the number of the fleets have decreased slowly. At the same time the U.S. fleet have decreased slowly, but with more advanced ships.
The RAN will have gone from 3 guided missile destroyers with approximately 120 standard missiles to 6 guided missile frigates with 240 standard missiles and harpoons, to 8 frigates with 64 sea sparrow missiles, to 256 evolved sea sparrow missiles along with 64 harpoons. One can easily see an improvement in the capability of the missiles and more of them. I'm not sure of the makeup of the VLS cells of the new air warfare destroyers, but there will likely be more than the 40 standard missiles in the magazines of the Adams class destroyers or the Adelaide class frigates.
One has to admire a huge increase in the number of missiles with the ESSM quad pack upgrade of the Anzac class and O.H.Perry class.