How often does sexual orientation modification occur?

I wanted to clarify an earlier post about the experience of Nicholas Cummings at Kaiser-Permanente. This revised article suggests a 13.4% rate of change for homosexuals who sought sexual reorientation from Kaiser therapists in the 1960s-1980s.

Dr. Cummings estimates as many as 16,000 clients sought therapy due to dissatisfaction with their sexuality during that period and that 67% reached a good outcome (meaning they either achieved a heterosexual adjustment or affirmed a gay identity). Of those, 20% were assessed as having redirected their sexuality toward a heterosexual adaptation, yielding a figure of 13.4% for the entire group. There were many more homosexual clients who sought therapy for the usual reasons people do and these people are not included in the numbers above.

The article is still draft at this point but I thought it might make for some good discussion.