“The average age of congregations was 61, with many above that, he said.”
Um, I’m guessing that about half are above that and half are below 61.
Nope. You’re confusing “median” with “average.”
Since it’s quite possible for youthful parishes to proliferate, it’s quite possible for there to be exceptionally young parishes, with average ages significantly below the median. OTOH, with the normal age so high, it’s not likely that there are parishes with average ages significantly above the median. This means that the average is likely to be below the median.
OTOH, most journalists don’t know the difference between median and average, either, so you’re probably right.