Study the graph and find what is the maximum percentage increase of tea from the previous year to the n

Let's calculate the percentage increase in tea production/consumption for each consecutive year interval:
1. From 2020 to 2021:

$$\text{Initial value (2020)}=13,\text{Final value (2021)}=15$$

$$\text{Percentage Increase}=\frac{15-13}{13}\times 100\%=\frac{2}{13}\times 100\%\approx 15.38\%$$

2. From 2021 to 2022:

$$\text{Initial value (2021)}=15,\text{Final value (2022)}=17$$

$$\text{Percentage Increase}=\frac{17-15}{15}\times 100\%=\frac{2}{15}\times 100\%\approx 13.33\%$$

3. From 2022 to 2023:

$$\text{Initial value (2022)}=17,\text{Final value (2023)}=20$$

$$\text{Percentage Increase}=\frac{20-17}{17}\times 100\%=\frac{3}{17}\times 100\%\approx 17.65\%$$

Comparing the values: $15.38\%$, $13.33\%$, and $17.65\%$.
The maximum percentage increase is $17.65\%$.