Seriously? Are there any number at all to show that wearables are a growth bet at this point? The Apple Watch (which entered the market three years ago!) has had an uptake at least an order of magnitude lower than the iPad, the last "next technological innovation" that turned out not to be. Tablets were hot for a while, but at the end of the day the smartphone market remains an order of magnitude bigger. The watch has never remotely been that hot.
Basically: innovation is hard. Wearables are not looking like the next big thing at this stage, and they are surely not going to save Apple from the expected downturn in smartphone sales.