$2.$ Explain which funds were the most and least tax efficient in their operations.

Fund W$$ Fund X$$ Fund Y$$ Fund Z$$

Assets under Management, Avg. for past $12$ months $($mil$)$ $$289\mathrm{.}4$ $$653\mathrm{.}7$ $$1298\mathrm{.}4$ $$5567\mathrm{.}3$

Security Sales, past $12$ months $($mil$)$ $$37\mathrm{.}2$ $$569\mathrm{.}3$ $$1453\mathrm{.}8$ $$437\mathrm{.}1$

Expense Ratio$0\mathrm{.}33\%0\mathrm{.}71\%1\mathrm{.}13\%0\mathrm{.}21\%$

Pretax Return, $3-$year avg.$9\mathrm{.}98\%10\mathrm{.}65\%10\mathrm{.}12\%9\mathrm{.}83\%$

Tax$-$Adjusted Return, $3-$year avg.$9\mathrm{.}43\%8\mathrm{.}87\%9\mathrm{.}34\%9\mathrm{.}54\%$

TAX COST RATIO: $0\mathrm{.}501\mathrm{.}610\mathrm{.}710\mathrm{.}26$