The overall pass rate is around 40% for the Assessment Center or at least it was 4 years ago. I dont know how the pass rate differs between first time and second time. I passed it second time. First time I only failed on the structured interview with the CCL assessor at the end, despite passing the computer and written tests with ease. Second time, I just managed to struggle through it with a borderline pass in the structured interview, but once again I passed the computer and written tests even more easily than the first time round. I would think the pass rate would be slightly higher for people going through their second attempt as I found it much easier the 2nd time. It feels like there is slightly less stress on the 2nd attempt because you know what to expect, while on the 1st attempt is stressful as I went in expecting it to be harder than it actually was.