Constructions like that can often be simplified by slices or by map. In the case of @years and @years_loop in the last example, the for(){push} construction is unnecessary. You already have a list of that data in the parens - just assign it directly. @years_loop is then an easy map,

my $curr_year = (localtime)[5] + 1900;
my @years = $cur_year - 100 .. $cur_year - 5;
my @years_loop = map { { year => $_ } } @years;
$template->param(years_loop => \@years_loop);
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The inner pair of curlies in the map produce a reference to an anonymous hash without needing to give it any temporary name.

After Compline,
Zaxo