@medengconfused If you say it’s growing at a CAGR of 5% (12% - 7%), you’d get a crude approximation. If you want a precise value, you should say it’s growing at 4.67% ((1 + 12%)/(1 + 7%) - 1).
In general, the formula is [ (1 + growth rate)/(1 + inflation rate) - 1 ]