My status in China Post Air mail shows NULL what does it means??

The first two parcels are in Bejing.
The third one is in Kolkata.
The fourth and the sixth are also in Beijing and the fifith is in Beijing and it is going to be sent.

Thank you for your prompt response. This orders which i made from online store ali express was previously ordered, i received my recent ordered request which i made recently however this orders r still pending in status its been almost a month now .


Why does it happens that some stuff are delayed more and some stuff reach quickly, also the seller has shipped the product a day after the order placement.