Add data for shell exercize

data.csv

+"Letter", "Frequency", "Percentage"
+    "A",  24373121,  8.1
+    "B",   4762938,  1.6
+    "C",   8982417,  3.0
+    "D",  10805580,  3.6
+    "E",  37907119, 12.6
+    "F",   7486889,  2.5
+    "G",   5143059,  1.7
+    "H",  18058207,  6.0
+    "I",  21820970,  7.3
+    "J",    474021,  0.2
+    "K",   1720909,  0.6
+    "L",  11730498,  3.9
+    "M",   7391366,  2.5
+    "N",  21402466,  7.1
+    "O",  23215532,  7.7
+    "P",   5719422,  1.9
+    "Q",    297237,  0.1
+    "R",  17897352,  5.9
+    "S",  19059775,  6.3
+    "T",  28691274,  9.5
+    "U",   8022379,  2.7
+    "V",   2835696,  0.9
+    "W",   6505294,  2.2
+    "X",    562732,  0.2
+    "Y",   5910495,  2.0
+    "Z",     93172,  0.0
+