What is the arithmetic average $\%$ return from the following seriers of year end porfolio values?

Year$/$$

$2019/$$$325000$

$2020/$$$318500$

$2021/$$$335750$

a $-2\mathrm{.}06\%$

b $-3\mathrm{.}71\%$

c $-1\mathrm{.}71\%$

d $-1\mathrm{.}64\%$

e $-1\mathrm{.}65\%$