How to calculate percentage warranty and percentage return by month

A B Warranty Return Warranty Return Warranty Return 3131 3484 2386 2317 2399 2359 2468 2547 2441 2653 3507 3711 552 386 580 352 423 468 2839 2501 0 1258 1237 1091 1243 1172 1101 1188 1275 1376 2823 2338 1705 1592 1798 761 785 858 660 691 679 756 788 363 385 878 727 0 3087 2916 3054 3138 3349 2510 3167 3156 3178 3462 3168 718 1526 1358 1914 0 0 553 564 816 644 492 884 780 463 412 1099 353 638 897 309 446 361 794 634 1185 367 451 1161 740 667 894 423 742 Product Type January 2011 February 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 September 2011 October 2011 November 2011 December 2011 January 2012 February 2012 March 2012 April 2012 May 2012 June 2012 July 2012 August 2012 September 2012 October 2012 November 2012 December 2012 January 2013 February 2013 March 2013 April 2013 May 2013 June 2013 July 2013 August 2013 September 2013 October 2013 November 2013 December 2013 January 2014 February 2014 March 2014 April 2014 May 2014 June 2014 July 2014 August 2014 September 2014 October 2014 November 2014 December 2014 January 2015 February 2015 March 2015 0 2442 2337 2414 2450 2423 2400 2406 2323 2329 3478 3691 0 2312 2302 2166 2362 2488 2325 2296 2418 2393 3515 3868 602 464 416 385 482 488 547 533 453 574 767 551 624 452 253 411 419 555 558 535 416 506 1223 1237 1188 1339 1180 1321 1360 1108 1316 2849 2316 610 721 653 709 719 685 3290 3436 2887 3166 3410 3421 3198 2937 3031 3467 2996 732 757 1824 1350 1730 595 0 0 279 778 642 1224 1151 1301 1289 1226 1345 1154 1255 1266 2538 2376 732 830 828 771 701 3180 3402 2742 3048 2959 2882 2791 3114 3019 3354 2976 370 1047 583 350 804 1069 0 2361 2429 2130 2295 2329 613 836 1565 1434 1617 800 500 504 460 857 0 2307 2254 2274 2375 771 935 563 444 510 468 293 429 614 594 389 485 584 573 534 517 545 1155 1090 1227 1281 1356 1225 1260 1222 1191 2703 2167 0 3117 3005 2784 2970 3236 2572 3247 3136 3069 3251 3266 861 720 745 732 610 618 758 3439 877 829 889 611 937 941 515 861 3560 0 2464 2351 2227 908 429 482 190 1521 A B Warranty Return Warranty Return Warranty Return 3131 3484 2386 2317 2399 2359 2468 2547 2441 2653 3507 3711 552 386 580 352 423 468 2839 2501 0 1258 1237 1091 1243 1172 1101 1188 1275 1376 2823 2338 1705 1592 1798 761 785 858 660 691 679 756 788 363 385 878 727 0 3087 2916 3054 3138 3349 2510 3167 3156 3178 3462 3168 718 1526 1358 1914 0 0 553 564 816 644 492 884 780 463 412 1099 353 638 897 309 446 361 794 634 1185 367 451 1161 740 667 894 423 742 Product Type January 2011 February 2011 March 2011 April 2011 May 2011 June 2011 July 2011 August 2011 September 2011 October 2011 November 2011 December 2011 January 2012 February 2012 March 2012 April 2012 May 2012 June 2012 July 2012 August 2012 September 2012 October 2012 November 2012 December 2012 January 2013 February 2013 March 2013 April 2013 May 2013 June 2013 July 2013 August 2013 September 2013 October 2013 November 2013 December 2013 January 2014 February 2014 March 2014 April 2014 May 2014 June 2014 July 2014 August 2014 September 2014 October 2014 November 2014 December 2014 January 2015 February 2015 March 2015 0 2442 2337 2414 2450 2423 2400 2406 2323 2329 3478 3691 0 2312 2302 2166 2362 2488 2325 2296 2418 2393 3515 3868 602 464 416 385 482 488 547 533 453 574 767 551 624 452 253 411 419 555 558 535 416 506 1223 1237 1188 1339 1180 1321 1360 1108 1316 2849 2316 610 721 653 709 719 685 3290 3436 2887 3166 3410 3421 3198 2937 3031 3467 2996 732 757 1824 1350 1730 595 0 0 279 778 642 1224 1151 1301 1289 1226 1345 1154 1255 1266 2538 2376 732 830 828 771 701 3180 3402 2742 3048 2959 2882 2791 3114 3019 3354 2976 370 1047 583 350 804 1069 0 2361 2429 2130 2295 2329 613 836 1565 1434 1617 800 500 504 460 857 0 2307 2254 2274 2375 771 935 563 444 510 468 293 429 614 594 389 485 584 573 534 517 545 1155 1090 1227 1281 1356 1225 1260 1222 1191 2703 2167 0 3117 3005 2784 2970 3236 2572 3247 3136 3069 3251 3266 861 720 745 732 610 618 758 3439 877 829 889 611 937 941 515 861 3560 0 2464 2351 2227 908 429 482 190 1521