While this is a good sales pitch, we can’t provide numbers without serious scientific study on this. A number of sprinkler controller companies are throwing out numbers that no one knows how they obtained those.
If you want an approximate idea of water savings: the log shows the average watering percentage every day. When that number is less than 100%, you are saving water compared to a traditional controller that doesn’t use automatic weather-based adjustments. So from this percentage (and total amount of water consumption) you can find out the amount of savings. Because different locations have different weather, the savings can vary considerably over geographic areas. In the end, throwing out an average number or ‘up to’ number doesn’t make much sense without any serious research.