vertical analysis in financial management

\begin{tabular}{|l|r|r|r|r|} \hline & 31-Mar-15 & 31-Mar-16 & 31-Mar-17 & 31-Mar-18 \\ \hline Total Revenue & 30,00,00,000 & 33,60,00,000 & 37,50,00,000 & 40,50,00,000 \\ \hline Cost of Revenue & 19,50,00,000 & 20,83,20,000 & 24,37,50,000 & 26,73,00,000 \\ \hline Gross Profit & 10,50,00,000 & 12,76,80,000 & 13,12,50,000 & 13,77,00,000 \\ \hline Total Operating Expenses & 5,77,50,000 & 7,66,08,000 & 8,00,62,500 & 8,53,74,000 \\ \hline Operating Income or Loss & 4,72,50,000 & 5,10,72,000 & 5,11,87,500 & 5,23,26,000 \\ \hline Interest Expense & 1,27,57,500 & 1,53,21,600 & 1,38,20,625 & 1,72,67,580 \\ \hline Income Before Tax & 3,44,92,500 & 3,57,50,400 & 3,73,66,875 & 3,50,58,420 \\ \hline Income Tax Expense & 1,20,72,375 & 1,07,25,120 & 1,12,10,063 & 1,05,17,526 \\ \hline Net Income & 2,24,20,125 & 2,50,25,280 & 2,61,56,813 & 2,45,40,894 \\ \hline \end{tabular} A. Perform the vertical analysis on the income