I don't have the brain to do the maths today but here are some figures to play with [I can't do copypaste for this article ...] 1984 10,000 megatons equivalent TNT 4.7 bn population =2.1 tons per person (~41 cubic feet)
~~~~~~ 2018 What could 1 Trident submarine do? 1 submarine carries: – Up to 8 missiles – Up to 40 warheads ... Total explosive power of 40 warheads is equal to: – 4,000,000 tonnes of TNT – about 300 Hiroshima bombs – more than all bombs dropped in World War II
2018 number of warheads estimated ... Total: 14,200