"since_year","till_year","Total","Graph"
"800","899","1",""
"1500","1599","3",""
"1600","1699","87","="
"1700","1799","323","==="
"1800","1899","3517","==================================="
"1900","1999","6583","=================================================================="
"2000","2099","247","=="
"9500","9599","1",""