Solve for the unknown number of years in each of the following. $($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$],[$$ $520,,10,\%,$$ $1,367],[770,,11,,1,793],[18,000,,16,,229,716],[21,100,,13,,276,052]]$