It is a difficult question you pose, having regard to many vagaries, it would seem. During the past year(mainly returning from Mexico), on a half dozen occasisons or more, I don't ever recdall waiting more than 20 minutes. On Tuesday, coming back from Buenos Aires, a mechanical delay in Lima resulted in a delayed LAX arrival of 8:50 for a 10:10 connecting flight to YVR. As it was not in the early evening as with the Mexican connections I thought the connection would be very problematic; however, although the securtity line was fairly long, 3 lanes were open and it took about 20 minutes. As it looked worse than it actually was, we tried the "Gold Line" request and "tight connection" plead but it was rebuked, period. The bottom line, from my experience, I have never waited much more than 20 minutes and very often it is less.