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$],[$$$,8,\%,$$$,2,055],[1,200,,6,\%,4,650],[2,891,,11,\%,396,620],[34,705,,18,\%,226,940],[34,400,,,,]]$