A wet flue gas analysis in vol$\%$ from an FCC regenerator is as follows:

N$2$: $81\%,$ CO$2$: $12\%,$ CO: $2\%,$ O$2$: $1\%,$ and H$2$O: $4\%.$

What is the hydrogen content $($as wt$\%)$ of the coke burnt$)$ in the regenerator? Assume that the coke burnt in the regenerator consists only of carbon and hydrogen and dry air is used to burn the coke.