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