Before giving you a concrete reply to your query please clarify the following :-
1. when you say Earning, does it mean Gross or Basic.
2. What was the reason for increase of Earning in the month of February.
Your inputs on the above queries will make it easy for all the learned members to give their inputs on the query raised by you.
12th October 2016 From India, Mumbai
Minimum statutory bonus is 8.33% of 7000 or state minimum wages whichever is higher. You can read my blog: Interpreting Payment of Bonus (Amendment) Act, 2015 | CompliFacts for more details.
Hope this clarifies you doubts.
16th October 2016 From India, Delhi