for nn in 00 01 02 03 04 05 06 07 08 09 10 11 12 ; do
    rename _g${nn}. . *
done

for  nn in `seq 73 99` ; do 
    rename _g${nn}. _ *
done

rename .3h _3h *

for year in `seq 1979 2018` ; do
    rename ${year}. ${year}- *
done
