Rapid DataBase size Increase's nearly 30Gb for SAP B1 8.81 PL5

Hello Experts,

As i am with a big doubt at database tunning level and decreasing data for space allocation in database.As one of my client is using sap b1 8.81 pl5.

The data is from 2013 April 1st to tilldate in the database,the size of the database is 30gb.how can i reduce the database size to certain size or how can shrink my database.As the mdf file is 30Gb and ldf file is 1mb.

According to the forums i have been done process at Administration-General setting-Services-History-Previously it was 10,now i have been changed to 1 and runned the addon at the object updation level.Apparently,the records are cleaned but the size of the database is still in the same process(30Gb). Aitm-prevoiusly it was around 100000 transaction,but after my updation of the items it came around 25000 and list of the items are 25000 My problem is for 1 year it is around 30gb.what will be the estimation for couple of years. solution would be greatly appreciated.Kindly,please suggest me the process to do the shrinking and reducing the size of the database.