Trick On Averaging Numbers

I am looking for the correct way to average a group of numbers.

I know the formula but it doeskin work correct.

I am trying to average this numbers below.

Now when I do this I use this formula

=AVERAGE(G1:G17)

and get this result
-33.079

Now the only problem is, with baseball lines +100 and -100 are both the same and there is never and two or one digit lines like
-4
or -88

its always at min -101 or +101

127
163
146
-119
-124
-139
119
-133
-113
-137
-130
-142
-101
-104
114
111
-111