How fast will I lose weight if I...?

How fast will I lose weight if I eat a healthy vegan diet of 1000-1200 calories, with exercise like walking (more like trudging, there is a lot of snow!), shovelling aforementioned precipitation, playing with the dog, cleaning, and yoga? I am 17, 5'5 and about 130 lbs, I would like to be 115. Thank you.