Transpose random series of cells

[brian]

I have a 60,000 long series of items that correspond with a range of
values. I need to automatically transpose the corresponding values so
that they can be combined into one cell.

Here's what I have:

1.2101R 1992
1.2101R 1993
1.2101R 1994
1.2101R 1995
1.2102G 1986
1.2102G 1987
10.1101G 1963
10.1101G 1964
10.1101G 1965
10.1101G 1966
10.1101G 1967
10.1101G 1968

Here's what I need
1.2101R 1992 1993 1994 1995
1.2102G 1986 1987
10.1101G 1963 1964 1965 1966 1967 1968

As you can see there are different quantities with each item.