David's tomato plant was $\displaystyle{12}\frac{{1}}{{5}}\usepackage{cmbright}\Huge\$ inches tall at the end of Week 1. The tomato plant was $\displaystyle{20}\frac{{2}}{{3}}\usepackage{cmbright}\Huge\$ inches tall at the end of Week 2. How many inches did the tomato plant grow during Week 2?