With your hint, I was able to do the following 

perl -F':' -lane '
push @{$h{$F[1]}}, [$F[0],$_] }{
print $_->[1] for map { splice [sort {$b->[0] <=> $a->[0]} @{$h{$_}}],
+0,4 } keys %h' file
20470:ZM:Samfya:Africa
20149:ZM:Sesheke:Africa
18638:ZM:Siavonga:Africa
699385:ZW:Bulawayo:Africa
61739:ZW:Chinhoyi:Africa
47294:ZW:Chegutu:Africa
37423:ZW:Bindura:Africa

[download]

Thanks LanX, your guidance was much appreciated.

In reply to Re^4: Using map function to print few elements of list returned by sort function by jaypal
in thread Using map function to print few elements of list returned by sort function by jaypal

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