"since_year","till_year","Number","Graph"
"200","299","1",""
"1500","1599","2",""
"1600","1699","93","="
"1700","1799","330","==="
"1800","1899","3554","===================================="
"1900","1999","14227","=============================================================================================================================================="
"2000","2099","3927","======================================="