I definitely read this somewhere, but after I read it, I could not find where I had read it when I went back to look for it. So you will have to take my word for it.
Pre-symptomatic – New infections coming from an infected person who has not yet developed symptoms: 46%.
Symptomatic – New infections coming from an infected person who has already developed symptoms: 40%.
Environmental – New infections comes from some environmental contact with the virus: 10%.
Asymptomatic – New infections come from a person that will never develop any symptoms: 4%.
As you can see, almost all infections come from people in the pre-symptomatic and symptomatic phases of the infection. Few infections come from touching infected surfaces and even fewer come from asymptomatic persons who never develop illness.