Database growth how could we plot ?

Dear support,

I would like to know is there any way to plot database growth in oracle , as my cutomer needs reason why there is database growth of 2 GB in first week of month and why it was 0.5 GB in next week . Off course we can find how much Database growth happened by history option. but could we find out in which tables growth happened over last few weeks and why ?

One way is to maintain tables information over every week and then monitor growth in particular tables in next week , but i am talking about already passed weeks ( history ) . can we find those by history for last 2 weeks.As we didnt maintain any table level info.

Best Regards,

AjitR