Gross Income Multiplier

In alternative investments they talk about this gross income multiplier…my question is, is this calculated with the potential gross income or with effective gross income (subtracting out vacancy and collection losses)…I believe it is potential gross income (rent income if fully occupied + other income) but can someone confirm? It is shown on pages 17-20 in schweser book 4

check out CFAI book 5 pg 32. I think it is gross potential