Not to split hairs again, but those numbers were for adults only. But we get the idea...
Here's the breakdown from the site you referenced. This shows 2004 count for kids and adults.
Catholics: 71,796,719
Baptist: 47,744,049
Meth/Wesln: 19,969,799
Lutheran: 13,520,189
Presbyterian: 7,897,597
Pentecostal/Charismatic: 6,219,569
Episcopalian/Anglican: 4,870,373
Judaism: 3,995,371
LD Saints/Mormon: 3,806,258
Churches of Christ: 3,659,483
Congregational/UCC: 1,944,762
Jehovah's Witnesses: 1,878,431
Assemblies of God: 1,560,890