Do you have a source for this or is it just a guess?
“What would you say if I told you that only 30% of modern Catholics believe in the Real Presence? Well, it’s true. A mere 30% of Catholics today believe that the sacrament of Holy Communion is actually Jesus, the Son of God. Many think, “Oh, sure, it’s a symbol of God”. But, no, it’s the real thing. Christ instituted the sacrament of Holy Communion in order to remain with us until the end of time (Jn 14:18). He intended us to believe in Him and, doing so, eat His Body and drink His Blood so that our life would be eternal. If we do not believe, we are not fulfilling His plan. Furthermore, the deeper our trust in this Presence, the more surely we will be saved; the more surely we will be sanctified; and the more effectively — beyond our wildest dreams” -
Catholic forums
I used to have the actual survey from a Catholic college on my old computer...but this is from Catholic answers
In January 1992, the St. Augustine Center Association sponsored a Gallup poll, called “A Gallup Survey of Catholics regarding Holy Communion.”Source.
This poll, which included telephone interviews of 519 U.S. Catholics during the period of December 10, 1991, to January 19, 1992, revealed that1) 29% of Catholics believe that when receiving Holy
Communion, they are receiving bread and wine, which symbolize the spirit and teachings of Jesus Christ, and in so doing are expressing their attachment to His Person and words.2) 24% of Catholics believe that when receiving Holy
Communion, they are receiving the Body and Blood of Christ, which has become that because of their personal belief.3) 10% of Catholics believe that when receiving Holy
Communion, they are receiving bread and wine, in which Jesus Christ is really and truly present.4) 8% of Catholics hold some other non-Catholic belief.
5) Only 30% of Catholics believe that they are really and
truly receiving the Body and Blood, Soul and Divinity of our Lord Jesus Christ under thse appearance of Bread and Wine.
Those who believe in the Real Presence were divided up among in the confusion of the five answers which were read to them over the phone.