Double-decker graves in Britain

There was a science fiction novel I read perhaps thirty years ago (the title of which escapes me at the moment) in which the living area on a future earth was so consumed by graveyards that humanity had to move to other planets and only return here to visit the cemetaries.

Perhaps that's beginning to come true.

Human remains are to be dug up and re-buried deeper in the ground in double-decker graves to tackle a shortage of space for new burials... only graves more than 100 years old that are no longer visited will be considered for the scheme.

A Government report last year found that burial space in England and Wales will be full in 30 years, while some urban boroughs are already out of room...

Almost a third of the roughly 600,000 people who die each year in Britain are buried.

I was surprised by the final sentence; I would have thought the percentage would be higher.