The yield on a general obligation bond for the city of Riyadh fluctuates with the market. The monthly quotations for $2023$ are given in following table:

Month

Yield

January

$9\mathrm{.}51$

February

$10\mathrm{.}11$

March

$10\mathrm{.}52$

April

$10\mathrm{.}62$

May

$10\mathrm{.}75$

June

$11\mathrm{.}15$

July

$11\mathrm{.}95$

August

$11\mathrm{.}25$

September

$10\mathrm{.}85$

October

$11\mathrm{.}66$

November

$11\mathrm{.}75$

December

$10\mathrm{.}85$ evaluate MSE