Assign serial number to observations

[Allaluiah]

You are unnecessarily duplicating 

https://communities.sas.com/t5/New-SAS-User/Split-dataset/m-p/517827#M3432

wonder why do you have to do that over and over

[ChrisNZ]

Why create new tables?

Or even a new variable?

Why not process using firstobs= and osb= ?

  proc ... data=XX(firstobs=1 obs=5000);

...

  proc ... data=XX(firstobs=5001 obs=10000);

...

etc

This can easily be managed in a macro.