HOW MANY ROUNDS SRILA PRABHUPADA CHANTED?

Srila Prabhupada was always in the thoughts of Krishna.

So, he should be considered as if chanting all the 24 hrs.

Ok, how many rounds Srila Prabhupada chanted? 

H.H.Tamal Krishna Gosvami’s Diary says:

"Many years ago, he (Shrila Prabhupada) was chanting sixty-four rounds, then gradually less, until a number of years ago it was SIXTEEN."