How to add new column to Dataframe

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3

thank you,

I have another problem,
my dataframe look like this,
the columns names x1,x2…x8 are gene’s names.
and 0,1,2, stands for genotypes.
and the column IID is for individuals names and they grouped in number 10004,
now I want to have avarage genotype for group 10004,
how can I do that?

 Row │ Herd.when.genotyped  IID        x1        x2        x3        x4        x5        x6        x7        x8       
     │ Int64                Int64      Float64?  Float64?  Float64?  Float64?  Float64?  Float64?  Float64?  Float64? 
─────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1 │               10004  410240170       2.0       1.0       2.0       2.0       1.0       2.0       1.0       1.0
   2 │               10004  412396339       2.0       0.0       0.0       2.0       2.0       1.0       1.0       0.0
   3 │               10004  412442014       2.0       2.0       1.0       2.0       1.0       1.0       2.0       0.0
   4 │               10004  412409256       2.0       1.0       0.0       2.0       2.0       0.0       2.0       0.0
   5 │               10004  412419664       2.0       2.0       0.0       2.0       1.0       1.0       2.0       1.0
   6 │               10004  412442177       1.0       2.0       2.0       1.0       1.0       2.0       2.0       2.0
   7 │               10004  412556442       2.0       1.0       2.0       2.0       2.0       2.0       2.0       1.0
   8 │               10004  412502732       2.0       1.0       0.0       2.0       2.0       1.0       2.0       0.0
   9 │               10004  412490450       2.0       1.0       1.0       2.0       2.0       2.0       2.0       2.0
  10 │               10004  412788155       2.0       1.0       2.0       2.0       1.0       2.0       2.0       1.0