This week in numbers

25

The Great Barrier Reef lost half of its coral populations in the last 25 years. Scientists say the decline will continue without steps to mitigate the effects of climate change.

60

Mars at present is a mere 60 million km away from Earth. At its farthest point the red planet is 400 km away.

20

Caleb Clarke, picked to start in the rugby test at Eden Park, is son of All Black Eroni Clarke. Twenty fathers and sons have worn the black jersey.

40

San Diego Zoo staff have cloned a pony by fusing cells taken from an endangered Przewalski’s horse at the zoo 40 years ago with a domestic mare.

34

Cricketing great John R. Reid, who has died at 92, captained New Zealand in 34 tests, including the team’s first three victories. .

5.2

million Americans cannot vote because they have been convicted of crimes, including 2m who have served their sentence.