use strict;
use warnings;
use Data::Dumper;
my %values;
for my $line (@lines) {
    chomp $line;
    my ($epoch, $d, $m, $y, $value1, ...) = split ' ', $line;
    $values{$epoch}->{count}++;
    $values{$epoch}->{value1_sum} += $value1;
    ...
}

for my $epoch (keys %values) {
    my $value1_sum = delete $values{$epoch}->{value1_sum};
    $values{$epoch}->{value1} = $value1_sum / $values{$epoch}->{count};
    ...
}
print Dumper \%values;