By analyzing the data below representing foreign exchange reserves, answer the question:

For which year is the percentage increase of foreign exchange reserves over the previous year the highest?

Let's calculate the percentage increase for the growth years:
1. **For year $1993\text{-}1994$ ** (compared to $1992\text{-}1993$):

$$\text{Increase}=4201-2520=1681$$

$$\text{Percentage Increase}=\left(\frac{1681}{2520}\right)\times 100\approx 66.71\%$$

2. **For year $1994\text{-}1995$ **:
There is a decrease ($4201\to 3720$).
3. **For year $1995\text{-}1996$ ** (compared to $1994\text{-}1995$):

$$\text{Increase}=5040-3720=1320$$

$$\text{Percentage Increase}=\left(\frac{1320}{3720}\right)\times 100\approx 35.48\%$$

4. **For year $1996\text{-}1997$ **:
There is a decrease ($5040\to 3120$).

Comparing the values, the highest percentage increase occurs in the year $1993\text{-}1994$ ($66.71\%$).