1. Clause, prior to/before Verb-ing

- The number of tourists to A City experienced an increase to 50,000 in 1995, before hitting a free fall to 25,000 in 2000.

2. Clause, after Verb – ing

- The figure for tourists to A City hit a free fall to 25,000 in 2000, after undergoing an increase to 50,000 in 1995.

3. There (clause), followed by + Noun Phrase

- There was a dramatic growth in the number of tourists to A City to 50.000 in 1995, followed by a sharp decrease to 25,000 in 2000.

4. As / Whereas/ While X (clause), Y (clause)

- While the figure for tourists to A City went up dramatically to 50,000 in 1995, the quantity to B City plummeted to 30,000 at the same time.

5. In comparison to/with X, which (clause), Y (clause)

- In comparison with the number of tourists to A City, which witnessed a dramatic increase to 50,000 in 1995, the quantity to B City plummeted to 30,000 at this time.

6. X (clause), Verb-ing, which (clause).

- The quantity of tourists to A City went through a period of dramatic increase to 50,000 in 1995, exceeding the number to B City, which had only 30,000.

Note: Besides the structures, the highlighted phrase can also help you improve your score.