https://www.berkeleytime.com/grades/?course1=2321-all-all&course2=2323-all-all&course3=2327-all-all
Looks like the percentages of students earning B+ or higher grades in the L&S CS prerequisites are:
49% CS 61A
59% CS 61B
47% CS 70
(B+ is 3.3 in GPA calculations.)