"since_year","till_year","Number","Graph"
"1720","1729","1",""
"1730","1739","3",""
"1740","1749","5",""
"1750","1759","8",""
"1760","1769","8",""
"1770","1779","10","="
"1780","1789","21","="
"1790","1799","16","="
"1800","1809","30","=="
"1810","1819","23","="
"1820","1829","26","="
"1830","1839","39","=="
"1840","1849","47","=="
"1850","1859","45","=="
"1860","1869","45","=="
"1870","1879","32","=="
"1880","1889","62","==="
"1890","1899","51","==="
"1900","1909","44","=="
"1910","1919","52","==="
"1920","1929","51","==="
"1930","1939","37","=="
"1940","1949","49","=="
"1950","1959","45","=="
"1960","1969","61","==="
"1970","1979","28","="
"1980","1989","26","="
"1990","1999","22","="
"2000","2009","23","="
"2010","2019","12","="