Louie the turtle was born with $4$ squares on his shell, as in the first picture below. When he was $1$ year old, $12$ new squares appeared around the old squares, as in the second picture below. Each year, a new group of squares appeared around the old squares.
**How many new squares appeared on Louie's shell each year? Extend the pattern and fill in the blanks in the chart below.**
Age | New squares
:-: | :-:
$0$ | $4$
$1$ | $12$
$2$ | [[☃ input-number 1]]
$3$ | [[☃ input-number 2]]