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:
| Name |  | Local names | Sort | Canton(s), neighboring countries | Area in km² | Elevation\nm | max. depth\nin meter |
| --- | --- | --- | --- | --- | --- | --- | --- |
| Lake Geneva |  | Lac Léman, Lac de Genève | Geneva | Geneva, Vaud, Valais, France | 580.03 | 372.0 | 310 |
| Lake Constance |  | Bodensee | Constance | St. Gallen, Thurgau, Austria, Germany | 536.00 | 395.6 | 252 |
| Lake Neuchâtel |  | Lac de Neuchâtel, Neuenburgersee | Neuchâtel | Berne, Fribourg, Neuchâtel, Vaud | 215.20 | 429.4 | 153 |
| Lake Maggiore |  | Lago Maggiore | Maggiore | Ticino, Italy | 210.12 | 193.5 | 372 |
| Lake Lucerne |  | Vierwaldstättersee | Lucerne | Lucerne, Nidwalden, Obwalden, Schwyz, Uri | 113.72 | 433.6 | 214 |
| Lake Zurich |  | Zürichsee | Zurich | St. Gallen, Schwyz, Zurich | 88.17 | 405.9 | 136 |
| Lake Lugano |  | Ceresio, Lago di Lugano | Lugano | Ticino, Italy | 48.67 | 270.5 | 288 |
| Lake Thun |  | Thunersee | Thun | Berne | 47.74 | 557.8 | 215 |
| Lake Biel |  | Lac de Bienne, Bielersee | Biel/Bienne | Berne, Neuchâtel | 39.51 | 429.1 | 74 |
| Lake Zug |  | Zugersee | Zug | Lucerne, Schwyz, Zug | 38.41 | 413.6 | 198 |
| Lake Brienz |  | Brienzersee | Brienz | Berne | 29.81 | 563.7 | 260 |
| Lake Walen |  | Walensee | Walen | Glarus, St. Gallen | 24.16 | 419.0 | 150 |
| Lake Murten |  | Murtensee, Lac de Morat | Murten | Fribourg, Vaud | 22.80 | 429.2 | 46 |
| Lake Sempach |  | Sempachersee | Sempach | Lucerne | 14.36 | 503.8 | 87 |
| Sihlsee |  | Sihlsee | Sihl | Schwyz | 10.72 | 889 | 23 |
| Lake Hallwil |  | Hallwilersee | Hallwil | Aargau, Lucerne | 10.21 | 448.7 | 47 |
| Lac de la Gruyère | ↑ | Lac de la Gruyère | Gruyère | Fribourg | 9.60 | 677 | 75 |
| Lac de Joux and\nLac Brenet | * | Lac de Joux and\nLac Brenet | Joux | Vaud | 9.56 | 1004 | 34 |
| Greifensee |  | Greifensee | Greifensee | Zurich | 8.17 | 435.1 | 34 |
| Lake Sarnen |  | Sarnersee | Sarnen | Obwalden | 7.38 | 468.4 | 52 |
| Ägerisee |  | Ägerisee | Aegeri | Zug | 7.25 | 723.9 | 82 |
| Lake Baldegg |  | Baldeggersee | Baldegg | Lucerne | 5.24 | 463.0 | 66 |
| Lago di Livigno | ↑ | Lago di Livigno | Livignio | Italy, Grisons | 4.71 | 1805 | 119 |
| Schiffenensee | ↑ | Schiffenensee, Lac de Schiffenen | Schiffenen | Fribourg | 4.25 | 532 | 38 |
| Wägitalersee | ↑ | Wägitalersee | Waegital | Schwyz | 4.18 | 900 | 65 |
| Lago di Lei | ↑ | Lago di Lei | Lei | Italy, Grisons | 4.12 | 1931 | 133 |
| Lake Sils |  | Silsersee, Lej da Segl | Sils | Grisons | 4.1 | 1797 | 71 |
| Lac des Dix | ↑ | Lac des Dix | Dix | Valais | 3.65 | 2365 | 227 |
| Lake Wohlen | ↑ | Wohlensee | Wohlen | Berne | 3.65 | 480 | 20 |
| Pfäffikersee |  | Pfäffikersee | Pfäffikersee | Zurich | 3.3 | 536 | 35 |
| Klöntalersee | * | Klöntalersee | Klöntalersee | Glarus | 3.29 | 847 | 47 |
| Lac d'Emosson | ↑ | Lac d'Emosson | Emosson | Valais | 3.27 | 1930 | 161 |
| Lake Silvaplana |  | Silvaplanersee, Lej da Silvaplauna | Silvaplana | Grisons | 3.1 | 1790 | 77 |
| Lake Lauerz |  | Lauerzersee | Lauerz | Schwyz | 3.1 | 447 | 14 |
| Grimselsee | ↑ | Grimselsee | Grimsel | Berne | 2.63 | 1908 | 100 |
| Lake Lungern | * | Lungerersee, Lungernsee | Lungern | Obwalden | 2.01 | 688 | 68 |
| Lac de Mauvoisin | ↑ | Lac de Mauvoisin | Mauvoisin | Valais | 2.08 | 1961 | 180 |
| Lago di Poschiavo | * | Lago di Poschiavo | Poschiavo | Grisons | 1.98 | 962 | 85 |
| Lai da Sontga Maria | ↑ | Lai da Sontga Maria | St. Maria | Grisons, Ticino | 1.77 | 1908 | 86 |
| Mattmarksee | ↑ | Mattmarksee | Mattmark | Valais | 1.76 | 2197 | 93 |
| Lago di Vogorno | ↑ | Lago di Vogorno | Vogorno | Ticino | 1.68 | 470 | 204 |
| Lac de Salanfe | ↑ | Lac de Salanfe | Salanfe | Valais | 1.62 | 1925 | 48 |
| Zervreilasee | ↑ | Zervreilasee | Zervreila | Grisons | 1.61 | 1862 | 140 |
| Lac de l'Hongrin | ↑ | Lac de l'Hongrin | Hongrin | Vaud | 1.60 | 1255 | 105 |
| Lago Bianco | * | Lago Bianco | Bianco | Grisons | 1.50 | 2234 | 53 |
| Lago Ritom | * | Lago Ritom | Ritom | Ticino | 1.49 | 1850 | 69 |
| Oberaarsee | ↑ | Oberaarsee | Oberaar | Berne | 1.47 | 2303 | 90 |
| Lai da Marmorera | ↑ | Lai da Marmorera | Marmorera | Grisons | 1.41 | 1680 | 65 |
| Lac de Moiry | ↑ | Lac de Moiry | Moiry | Valais | 1.40 | 2249 | 120 |
| Limmernsee | ↑ | Limmernsee | Limmern | Glarus | 1.36 | 1857 | 122 |
| Göscheneralpsee | ↑ | Göscheneralpsee | Göscheneralp | Uri | 1.32 | 1792 | 106 |
| Lago di Luzzone | ↑ | Lago di Luzzone | Luzzone | Ticino | 1.27 | 1606 | 181 |
| Klingnauer Stausee | ↑ | Klingnauer Stausee | Klingnau | Aargau | 1.16 | 318 | 8.5 |
| Albigna lake | ↑ | Lago da l'Albigna\nLägh da l'Albigna | Albigna | Grisons | 1.13 | 2163 | 108 |
| Oeschinen Lake | ↑ | Oeschinensee | Oeschinen | Berne | 1.11 | 1578 | 56 |
| Lago del Sambuco | ↑ | Lago del Sambuco | Sambuco | Ticino | 1.11 | 1461 | 124 |
Question:
what is the number of lakes that have an area less than 100 km squared?
Answer:
51