The top half is the future, the bottom half is the past, the exact middle is the present. (religion.blogs.cnn.com)
As you can see, though, it's kind of hard to keep the seam in the exact middle of my legs (but I still love them!). (have-clothes-will-travel.com)
That is the score achieved by the exact middle student in the year 12 class when their scores are ranked from lowest to highest. (teachermagazine.com.au)