Not an unreasonable conclusion. 1.) Google handles 92% of global search traffic 2.) extrapolate to the US (since it's likely the same, if not higher) : Google

Not an unreasonable conclusion. 1.) Google handles 92% of global search traffic 2.) extrapolate to the US (since it's likely the same, if not higher) : Google handles 92% of US search traffic 3.) Half of Google's US traffic comes from Apple devices (since Apple controls 60% of the smartphone market in the US).