Compare arrays and add missing key value to array [duplicate]

I have two arrays:

First

array (size=6)
0 => 
array (size=2)
  'Age' => string '25-34' (length=5)
  'Count' => string '45' (length=2)
1 => 
array (size=2)
  'Age' => string '55-64' (length=5)
  'Count' => string '1' (length=1)
 2 => 
array (size=2)
  'Age' => string '13-17' (length=5)
  'Count' => string '3' (length=1)
3 => 
array (size=2)
  'Age' => string '35-44' (length=5)
  'Count' => string '11' (length=2)
4 => 
array (size=2)
  'Age' => string '18-24' (length=5)
  'Count' => string '46' (length=2)
5 => 
array (size=2)
  'Age' => string '45-54' (length=5)
  'Count' => string '2' (length=1)

Second:

array (size=5)
0 => 
array (size=2)
  'Age' => string '65+' (length=3)
  'Count' => string '1' (length=1)
1 => 
array (size=2)
  'Age' => string '13-17' (length=5)
  'Count' => string '4' (length=1)
2 => 
array (size=2)
  'Age' => string '35-44' (length=5)
  'Count' => string '3' (length=1)
3 => 
array (size=2)
  'Age' => string '25-34' (length=5)
  'Count' => string '11' (length=2)
4 => 
array (size=2)
  'Age' => string '18-24' (length=5)
  'Count' => string '20 |' (length=4)

Now what here I am getting is that First array size is larger than Second one, so I need a solution for making the small size array similar to larger size array.

With same keys, and add value zero to new added keys value.