Looking on the internet deeply has found these results:

depends mostly on is the most popular phrase on the web.

depends mostly of 1336 results on the web	depends mostly on 1408,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
... clima" but there are other countries where tardar is used like retrasar ( reflexively). So, your question depends mostly of the country where you are speaking. Jun 26, 2015 ... His waveclear is really low and depends mostly of his ult, which is also his only source of AoE damage for teamfights. But what about his W? The actual importance of a specific component depends mostly of the wavelength of the measurement. The uncertainty (or noise) of the measurements caused�... Climatization energy consumption, in residential dwellings depends mostly of external loads, therefore, of the quality of the building envelope and ventilation�...	It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

depends mostly of

1336 results on the web

depends mostly on

1408,000 results on the web

More popular!

... clima" but there are other countries where tardar is used like retrasar ( reflexively). So, your question depends mostly of the country where you are speaking.
Jun 26, 2015 ... His waveclear is really low and depends mostly of his ult, which is also his only source of AoE damage for teamfights. But what about his W?
The actual importance of a specific component depends mostly of the wavelength of the measurement. The uncertainty (or noise) of the measurements caused�...
Climatization energy consumption, in residential dwellings depends mostly of external loads, therefore, of the quality of the building envelope and ventilation�...

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.