Sooladi Sapta Talas - why is this in a particular order?

[VishyamOS]

Hi Everyone,

Assuming this is probably a question that someone has already asked, i have searched the internet extensively, but in vain. Wonder if someone can throw light on this question that has irked me all this while.

I realise that the Sooladi Sapta Talas are listed in this particular order
Dhruva - I0II
Matya - IOI
Roopaka - OI
Jhampa - IUO
Triputa - IOO
Ata - IIOO
Eka - I

Why is this always in this order? and is there history behind this, surely someone would know the answer to this question?