Hello rwx---, and welcome to the Monastery!

You could reorganise the HoHoA into a HoHoH:

{
    "Population by Age and Gender" =>
    {
        "0-9"    => { Male => 220, Female => 180 },
        "10-19"  => { Male => 175, Female => 142 },
        "20-29"  => { Male => 260, Female => 265 },
    },
    "Family Households" =>
    {
        Married  => { Households => 145 },
        Divorced => { Households =>  60 },
        Single   => { Households => 162 },
    },
}
[download]

but this is still going to quickly become unwieldly. I strongly suggest you consider using a database instead. For example, the module DBD::SQLite can be used to create a database which occupies a separate file but requires no software outside of your Perl script.

Hope that helps,