Those of us who have not implemented ADS-B on our aircraft yet are probably seriously scrambling to get it done before the end of the year. There are about 211,000 GA aircraft in the United States. Around 54,000 GA aircraft have been equipped with ADS-B which is only about 25% of them. Many aircraft owners live in areas where they can continue to fly while avoiding the airspace where ADS-B equipment is required. This fact and the 25% ADS-B installation rate suggest to me that it might be a very long time before most GA aircraft are equipped with ADS-B. For those of us that fly in the Puget Sound area there will be no avoiding the ADS-B requirement by the end of this year.