Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Book series | Author | Original language | No. of installments | First published | Approximate sales |
| --- | --- | --- | --- | --- | --- |
| Nijntje ( Miffy ) | Dick Bruna | Dutch | 119 | 1955 — present | 85 million |
| Fear Street | R. L. Stine | English | 114 | 1989 — present | 80 million |
| The Vampire Chronicles | Anne Rice | English | 12 | 1976-2003 | 80 million |
| Pippi Longstocking | Astrid Lindgren | Swedish | 3 + 3 picture books | 1945-2001 | 80 million |
| OSS 117 | Jean Bruce | French | 265 | 1949–1992 | 75 million |
| Diary of a Wimpy Kid | Jeff Kinney | English | 7 | 2007–present | 75 million |
| Winnie-the-Pooh | A. A. Milne ; illustrated by E. H. Shepard | English | 2 | 1926–1928 | 70 million |
| Magic Tree House series | Mary Pope Osborne | English | 43 | 1992–present | 70 million |
| Fifty Shades of Grey | E. L. James | English | 3 | 2011–2012 | 70 million |
| Left Behind | Tim LaHaye , Jerry B. Jenkins | English | 16 | 1996 — 2007 | 65 million |
| A Series of Unfortunate Events | Lemony Snicket aka Daniel Handler | English | 13 | 1999–2006 | 65 million |
| Little House on the Prairie | Laura Ingalls Wilder | English | 12 | 1932–2006 | 60 million |
| Jack Reacher | Lee Child | English | 16 | 1997–present | 60 million |
| Discworld | Terry Pratchett | English | 39 | 1983–present | 55 million |
| Where's Wally? | Martin Handford | English | 13 | 1987–present | 55 million |
| Millennium Trilogy | Stieg Larsson | Swedish | 3 | 2005–2007 | 53 million |
| Men Are from Mars, Women Are from Venus | John Gray | English | 15 | 1992–present | 50 million |
| The Hardy Boys | various authors as Franklin W. Dixon | English | 190 | 1927–present | 50 million |
| The Bobbsey Twins | various authors as Laura Lee Hope | English | 72 | 1904–1979 | 50 million |
| Tarzan | Edgar Rice Burroughs | English | 26 | 1914–1995 | 50 million |
Question:
What are all approximate sales for the author Laura Ingalls Wilder?
Answer:
60 million