The term doesn't just mean "has an igpu" right? I'd guess the figure is higher than 90% if that's how you're defining it—most motherboards come with igpus now and certainly almost all laptop mainboards. Otherwise I'm not sure how you are defining it to find that figure!
There are other aspects IMO like the iGPU has to support memory translation and coherence but AMD and Intel have also had those features for years (even if the drivers don't use them).