a = int(input())
b = []
s = "%"
for i in range(a):
sum = 0
n = 0
b.append(input().split(" "))
for j in range(int(b[i][0])):
sum = sum + int(b[i][j+1])
sum = sum / int(b[i][0])
for j in range(int(b[i][0])):
if (sum < int(b[i][j+1])):
n = n+1
print("%.3f%s"%(100*n/(int(b[i][0])))%s)
YSA9IGludChpbnB1dCgpKQpiID0gW10KcyA9ICIlIgpmb3IgaSBpbiByYW5nZShhKToKICAgIHN1bSA9IDAKICAgIG4gPSAwCiAgICBiLmFwcGVuZChpbnB1dCgpLnNwbGl0KCIgIikpCiAgICBmb3IgaiBpbiByYW5nZShpbnQoYltpXVswXSkpOgogICAgICAgIHN1bSA9IHN1bSArIGludChiW2ldW2orMV0pCiAgICBzdW0gPSBzdW0gLyBpbnQoYltpXVswXSkKICAgIGZvciBqIGluIHJhbmdlKGludChiW2ldWzBdKSk6CiAgICAgICAgaWYgKHN1bSA8IGludChiW2ldW2orMV0pKToKICAgICAgICAgICAgbiA9IG4rMQogICAgcHJpbnQoIiUuM2YlcyIlKDEwMCpuLyhpbnQoYltpXVswXSkpKSVzKSA=