Error log says
Use of uninitialized value in division (/) at /var/www/html/beertracker/index.cgi line 1122, line 9832.
Use of uninitialized value in division (/) at /var/www/html/beertracker/index.cgi line 1146.
Use of uninitialized value in division (/) at /var/www/html/beertracker/index.cgi line 1146.
Illegal division by zero at /var/www/html/beertracker/index.cgi line 1146.
When there is no data for the current year.
Error log says Use of uninitialized value in division (/) at /var/www/html/beertracker/index.cgi line 1122, line 9832.
Use of uninitialized value in division (/) at /var/www/html/beertracker/index.cgi line 1146.
Use of uninitialized value in division (/) at /var/www/html/beertracker/index.cgi line 1146.
Illegal division by zero at /var/www/html/beertracker/index.cgi line 1146.