Equation to fit data

[fenixtx423]

I am modeling a natural process and have obtained the data below. I am trying to find an equation that fits the points but have not been successful yet. Any help is greatly appreciated. Thanks
X Y

0.000001	0.6687
0.0001	0.6737
0.0003	0.6876
0.0005	0.6986
0.0007	0.7116
0.0009	0.72
0.001	0.7273
0.0015	0.7462
0.002	0.7621
0.004	0.7797
0.006	0.7731
0.008	0.7589
0.01	0.7486
0.02	0.7056
0.04	0.6631
0.06	0.6435
0.08	0.6322
0.1	0.625

 

[Ishuda]

I am modeling a natural process and have obtained the data below. I am trying to find an equation that fits the points but have not been successful yet. Any help is greatly appreciated. Thanks
X Y

0.000001	0.6687
0.0001	0.6737
0.0003	0.6876
0.0005	0.6986
0.0007	0.7116
0.0009	0.72
0.001	0.7273
0.0015	0.7462
0.002	0.7621
0.004	0.7797
0.006	0.7731
0.008	0.7589
0.01	0.7486
0.02	0.7056
0.04	0.6631
0.06	0.6435
0.08	0.6322
0.1	0.625

Generally when trying to model a natural process, one tries to understand the behavior of the process to suggest a model. For example cell division is start with 1, divide have 2, two divide have 4, ... so you might expect an exponential growth given 'proper circumstances'.

For your data, if we are just picking models, I can think of several including something like
a[ 1/(x+b) - c/(x+d]
or maybe the part of the Airy function from about -2 or so on in the positive x direction or a Skellam distribution or ...