Average calculation of numbers with special characters

Hi All...

Wonder if someone could help me with this excel formula. I am trying to calculate the average for the values in two cells with numbers and special characters. The formula i am using is.

=SUMPRODUCT((SUBSTITUTE(SUBSTITUTE(D6:E9,"▼",""),"▲","")*1))/COUNTA(D6:E9)

it is coming up with #VALUE ERROR. And i can't get my head around. May be i am going through the thinking cramp in my head. Your help is much appreciated. I have also attached a sample file for you guys to have a look. Thanks in advance.