While we can never truly know, there is estimated to be 106 billion souls in Purgatory (not counting, sadly, the souls lost from abortion). There may be more or there may be less. Should that stop us from constantly praying for them? Not at all! There could be billions of eventual Saints that will turn and pray for us!
Question: So what does this mean?
Answer: It means we have a ton of praying to do!
Recite this prayer for them:
Eternal Father, I offer Thee the Most Precious Blood of Thy Divine Son, Jesus, in union with the Masses said throughout the world today, for all the Holy Souls in Purgatory, for sinners everywhere, for sinners in the Universal Church, those in my own Home and within my family. Amen.
Our Lord told St. Gertrude the Great that each time this is said Our Lord would release 1000 souls from Purgatory.