( last(//mysql.innodb_buffer_pool_pages_total) - 
last(//mysql.innodb_buffer_pool_pages_free) ) / 
( last(//mysql.innodb_buffer_pool_pages_total) + 
( last(//mysql.innodb_buffer_pool_pages_total) = 0 ) ) * 100 * 
( last(//mysql.innodb_buffer_pool_pages_total) > 0 )