The viewership figure released on Friday by the television tracking firm Nielsen did not include<br />statistics for PBS, C-Span or the Fox broadcasting affiliates that carried the hearing live.<br />Roughly 19.5 million Americans tuned in on Thursday to watch James B. Comey, the former F. B.I.<br />director, unspool the tale of his awkward, unsettling and, at times, ethically questionable encounters with President Trump.