Aswimming pool had 2.5 million liters of water in t some water evaporated, and then the million liters of water in it what percent of the water evaporated?

A swimming pool had 2.5 million liters of water in it. Some water evaporated, and then the pool only had 2 million liters of water in it. The water that evaporate would be: 2.5 million liters - 2 million liters = 0.5 million liters 

The percent of water evaporated would be:

percent of water evaporated: evaporated water/ original swimming pool volume * 100%
0.5 million liters / 2.5 million liters * 100%=
1/5 *100%= 20%