Question

As people, we depend on ____ percent of the freshwater supply of the world

Answer 1

I think there should be an options to choose. But I can provide you with official charts about the percentage of the freshwater supply of the world and you will choose the closest number from your options.
68% is in icecaps and glaciers;
30% is found in ground water; 
0.3% is found in lakes, rivers and swamps.