use Data::Dumper ;
my %devices;
for my $line (@df) {
    use Data::Dumper ;
    my %info;
    print Dumper (\%info);
    @info{@headers} = split /\s+/, $line;  # note the hash slice
    $info{capacity} = _percentage_to_decimal($info{capacity});
    $devices{ $info{mount} } = \%info;
    print Dumper(\%devices);
}