Hello, I have Excel 2007

I have a series of increasing numbers which have been trucated (rounded
down) to integers , eg

2, 2, 2, 3, 3, 3, 3, 4, 5, 5, 6, 6, 6 etc

The decimal part of the numbers has been 'lost' and cannot be recovered.

I want to 'smooth' the data to estimate the original numbers to 1 decimal
place, eg to give someting like

2.0, 2.4, 2.8, 3.1, 3.3, 3.6, 3.9, 4.5, 5.1, 5.7, 6.1, 6.4, 6.8,
....

I am ok at maths and could devise an algorithm to do this, but I wonder if
there is an Excel function which can do it more easily. I have looked at the
functions and cannot see anything obvious, but I might have missed
something.

Any ideas warmly welcomed.

Thanks

K