I think it's even more miniscule than you imply: my math tells me that 63.63mm (not even 1 centimeter) over a 63 year period.
This is the very kind of data I've been looking for "them" to admit for years.
And what of the very strong possibility that the side of the island where this is being measured is slowly sinking?
There are so doggone many variables in trying to measure sea level change. And we know that stats don't lie but liars always cook the stats.
1.1 mm/yr X 63 years = 69.3 mm = 6.93 cm