In $1978,$ the average book value of U$.$S$.$ Companies was $95\%$ of market value $($slightly under $1\mathrm{.}1$ times book value$)$; by $2021$ S&P firms were trading at $\_\_\_\_$ times book value.

Question $22$ options:

$4\mathrm{.}4$

$12\mathrm{.}8$

$75\%$

almost $2$