Interest Problem In C Language

/*--------INVERSTMENT PROBLEM -------*/
#define PERIOD 10
#define PRINCIPAL 5000.00
main()
{
	int year;
	float amount, value, inrate;
	amount=PRINCIPAL;
	inrate=0.11;
	year=0;

	while(year <= PERIOD)
	{
		print_r("%2d %8.2f\n",year, amount);
		value = amount + inrate * amount;
		year = year + 1;
		amount = value;		
	}
}

Output

0	5000.00
1	5550.00
2	6160.50
3	6838.15
4	7590.35
5	8425.29
6	9352.07
7	10380.00
8	11522.69
9	12790.00
10	14197.11