ddf count is 0

Fatal error: Uncaught DivisionByZeroError: Division by zero in /home/inthekibble/public_html/wp-content/themes/itk-theme/page-templates/calculations.php:40 Stack trace: #0 /home/inthekibble/public_html/wp-includes/template-loader.php(106): include() #1 /home/inthekibble/public_html/wp-blog-header.php(19): require_once('/home/inthekibb...') #2 /home/inthekibble/public_html/index.php(17): require('/home/inthekibb...') #3 {main} thrown in /home/inthekibble/public_html/wp-content/themes/itk-theme/page-templates/calculations.php on line 40