Which preposition to use with productiveness

of Occurrences 32%

The productiveness of July is portentous.

to Occurrences 1%

As he advances in life, as his powers ought to be coming to fuller maturity and his intellectual productiveness to its prime, just in the same degree the increasing seriousness of life multiplies such moments and deepens their remorse, and so the light of intellectual promise slowly goes out in impotent endeavour, or else in taking comfort that much goods are laid up, or, what is deadliest of all, in a soulless cynicism.

Which preposition to use with  productiveness