Step 1: Instead of converting every Profit/Expenditure ratio into a decimal percentage, compare the fractions pairwise using cross-multiplication to find the largest without decimals.
Step 2: Profit for each year: 2019 $=120-80=40$; 2020 $=150-90=60$; 2021 $=180-120=60$; 2022 $=200-140=60$; 2023 $=250-175=75$.
Step 3: The Profit/Expenditure fractions are: 2019 $=\frac{40}{80}$, 2020 $=\frac{60}{90}$, 2021 $=\frac{60}{120}$, 2022 $=\frac{60}{140}$, 2023 $=\frac{75}{175}$.
Step 4: Compare 2020 ($\frac{60}{90}$) with 2019 ($\frac{40}{80}$) using cross-multiplication: $60\times80=4800$ versus $40\times90=3600$. Since $4800>3600$, $\frac{60}{90}>\frac{40}{80}$, so 2020 beats 2019.
Step 5: Compare 2020 with 2021: both have profit $60$, but 2020 has the smaller expenditure ($90$ vs $120$), so $\frac{60}{90}>\frac{60}{120}$; 2020 also beats 2022 for the same reason ($90<140$). Compare 2020 with 2023: $60\times175=10500$ versus $75\times90=6750$; since $10500>6750$, $\frac{60}{90}>\frac{75}{175}$. So 2020 has the highest profit-to-expenditure ratio among all five years.
\[\boxed{2020}\]