1.   The incidence curve rose dramatically, and within just a few years this initial core quickly became saturated.

2.   But the sales curve is rising again.

3.   Paradoxically, this exhibition comes at a moment when the curve is rising and things are getting better.

4.   The irony is that when the cars were worst and service at its nadir, the sales curves were rising off the charts.

5.   A long, graceful curve rises skyward, dips suddenly and then resumes its ascent.