letter   #center   avg center   #other   avg other
--------------------------------------------------
a                                    2        52.5
b                                    2        52.5
c                                    1        55.0
d                                           
e                                           
f                                    1        55.0
g                                           
h                                           
i              1         52.0               
j                                           
k                                    3        52.3
l              1         50.0        2        53.5
m                                           
n                                    1        52.0
o                                           
p                                           
q                                           
r                                    2        51.0
s                                           
t                                           
u              1         55.0        1        50.0
v                                           
w                                    2        51.0
x                                           
y                                    1        52.0
z