Добрый день!
Собственно САБЖ.
private static function struct() 
{
	return [
		1  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		2  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		3  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		4  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		5  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		6  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		7  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		8  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		9  => ['plan' => 0, 'norm' => null, 'fact' => 0],
		10 => ['plan' => 0, 'norm' => null, 'fact' => 0],
		11 => ['plan' => 0, 'norm' => null, 'fact' => 0],
		12 => ['plan' => 0, 'norm' => null, 'fact' => 0],
	];
}
Циклы не хочу :)