According to the passage, what share of the Earth's water is the fresh water people depend on?

Seen from space, the Earth is mostly blue, and for good reason. The ocean covers about seventy per cent of the planet's surface, and it holds about ninety-seven per cent of all the Earth's water.

Most of the rest is locked away. About two per cent of the Earth's water is frozen in glaciers and ice caps. Less than one per cent is the fresh water that people, animals and crops depend on, and a tiny fraction floats in the air as water vapour.

The ocean is not only vast but deep. Its average depth is about 3,682 metres, more than three and a half kilometres. Throughout those depths there is life. In fact, the ocean is the largest space on the planet where living things can survive, and there is more life there than anywhere else on Earth.

Yet we know surprisingly little about it. Most of the ocean has never been explored, and before scientists can explore a place properly, they must first map it. So the planet's largest home for life is still, in large part, a place nobody has seen.