How to convert Nspt=50/220mm to Nspt in scale of 100

In Japan they convert it to 100/440mm(just double it, and that is not a formal or offical rule.) but it cannot be treated correct answer.
Because, even u blow 100 times it is not clear it can penetrate upto 440mm like the preceding if u blow 100times then it can be penerated upto over 440mm.......
So in my opinion it is more reasonable that just use 50 as it's maximum or using other downhole test.

Thank you, for your response. I know if I doubled that will not be good. What I mean is in order 1 to 100 (blows/300mm). My next analysis is based on blows/300mm of Nspt value in order 1 to 100.

What if I interpolate linearly to defined Nspt in scale of 100 (blows/300mm). For example:
--> Nspt=50/220mm
--> 50 + 50[(300/300)-(220mm/300mm)]=63 (blows/300mm)

I think this is more resonable than I doubled it. Is it right or not?
Thank you.

I also asked that question b4 in this forum so u can find it with advanced search on this site.
In advanced search type "chunil" into keywords and then tag button on "Handle".
Then u can find...What i posted b4~
Wish it is helpful~
^_^

Yeah I get that..but still blur for me. What is ur oppinion to my extrapolate?
TQ

If u should have the converted value...
Then urs a reasonable ..
and if i were then i would solve it in this way...
50:220 = x:300
then X = 68.18 and I will use 68 for the value.

But not sure.....
-_-.....
Good Luck..~ ^_^

If there is no relationship, I think I dont have any choice. I know that value will be conservative. If somebody know something about it please let me know.
Thank you and Thanks Chunil.