"since_year","till_year","Number","Graph"
"200","299","1",""
"800","899","12",""
"900","999","11",""
"1000","1099","21",""
"1100","1199","26",""
"1200","1299","43",""
"1300","1399","143","="
"1400","1499","498","====="
"1500","1599","1170","============"
"1600","1699","3275","================================="
"1700","1799","9266","============================================================================================="
"1800","1899","19608","===================================================================================================================================================================================================="
"1900","1999","21721","========================================================================================================================================================================================================================="
"2000","2099","2018","===================="