<?php
 
error_reporting(-1);

$sum = 10000;
$proc = 1.1;
$lvl = 16;

for ($year = 1; $year <= 20; $year ++)
{
	$lvl + $year = $lvl2;       /* ? */
	$sum*$year*$proc = $sum2;      /* ? */	
	echo "{$year}-ый год - получено {$sum2}, вложившему {$lvl2} \n";
}