I see this touted by all the "Old Rite" adherents.
I don't believe it; 100% of the Catholics who belonged to the Church when the "Old Rite" was all there was didn't attend Mass every Sunday.
I consider 60% attendance good, given that the average Sunday Mass attendance in the United States is 50%.
Second point: Your stats on current US Mass attendance are about 10 years out of date. The latest figures are more on the order of 20-30%, if my memory serves me well. So by that measure, your parish is one of the better ones. You should thank God for that. Many Americans belong to a parish without a priest assigned to it.
I still would be mighty obliged if you would answer the following question: how many vocations has your parish produced in the last 30 years? The parish where I grew up, which is has about 30,000 members and is thoroughly laden with the "spirit of vatican 2", produced exactly 1 vocation since 1970.