"since_year","till_year","Number","Graph"
"600","699","1",""
"700","799","18",""
"800","899","82","="
"900","999","123","="
"1000","1099","127","="
"1100","1199","56","="
"1200","1299","29",""
"1300","1399","9",""
"1400","1499","2",""
"1500","1599","20",""
"1600","1699","152","=="
"1700","1799","358","===="
"1800","1899","577","======"
"1900","1999","1006","=========="
"2000","2099","103","="