Having trouble understanding Gross aren’t Multiple

[Scott Shimala]

I’ve come across he formula for dealing with Gross Rent Multiplier, which is the selling price of the property/gross rent per year. 

The book I'm reading is using an example of a $200,000 house with an 8.5 GRM due to $1950/mo, or $23400/yr in rent (23400x8.5=200,070.

Just after, the book talks about improving the property so rent brings in more money per month/year, which increases Gross Rent Multiple. 

According to the formula, shouldn’t this decrease the Gross Rent Multiple? What am I missing?