If i have a matrix that looks like this:
Region Ålder Antal regpop Andel
[1,] "01 Stockholms län" "0 år" "28474" "2377081" "0.0119785568939384"
[2,] "01 Stockholms län" "1 år" "29033" "2377081" "0.0122137192632477"
[3,] "01 Stockholms län" "10 år" "29678" "2377081" "0.0124850604586045"
[4,] "01 Stockholms län" "100+ år" "524" "2377081" "0.000220438428475933"
[5,] "01 Stockholms län" "11 år" "29679" "2377081" "0.0124854811426283"
[6,] "01 Stockholms län" "12 år" "28956" "2377081" "0.0121813265934144"
[7,] "01 Stockholms län" "13 år" "28592" "2377081" "0.0120281976087479"
[8,] "01 Stockholms län" "14 år" "27572" "2377081" "0.0115990999044627"
[9,] "01 Stockholms län" "15 år" "27466" "2377081" "0.0115545073979389"
[10,] "01 Stockholms län" "16 år" "26691" "2377081" "0.0112284772794869"
[11,] "01 Stockholms län" "17 år" "26004" "2377081" "0.0109394673551301"
[12,] "01 Stockholms län" "18 år" "24996" "2377081" "0.0105154178591306"
[13,] "01 Stockholms län" "19 år" "24971" "2377081" "0.0105049007585354"
[14,] "01 Stockholms län" "2 år" "29268" "2377081" "0.0123125800088428"
[15,] "01 Stockholms län" "20 år" "24777" "2377081" "0.0104232880579164"
what should i do to order them from "0 år", "1 år", "2 år" ....."100+ år"