while ( my $line = <DATA> ) {
    next unless $line =~ /\d{3,}\.\d{3}-\d{3,}\.\d{3}/;
    my( $bytes ) = $line =~ /\s(\d+)\s*$/;
    if ( $bytes > $grenzwert ) { $data .= '1' }
    else                       { $data .= '0' }
}