Solve for the unknown number of years in each of the following:

Note: Do not round intermediate calculations and round your answers to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

$\backslash$table$[[$Present Value,Years,Interest Rate,Future Value$],[$$$,1,200,,,\%,$$$,2,055],[,2,891,,6,\%,,4,650],[,34,705,,11,\%,,396,620],[,34,400,,18,\%,,226,940]]$