Feature: Configure minimum share trading years

src/table/settings.ini

@@ -1424,6 +1424,19 @@ str      = STR_CONFIG_SETTING_ALLOW_SHARES
 strhelp  = STR_CONFIG_SETTING_ALLOW_SHARES_HELPTEXT
 proc     = InvalidateCompanyWindow
 
+[SDT_VAR]
+base     = GameSettings
+var      = economy.min_years_for_shares
+type     = SLE_UINT8
+def      = 6
+min      = 0
+max      = 255
+interval = 1
+str      = STR_CONFIG_SETTING_MIN_YEARS_FOR_SHARES
+strhelp  = STR_CONFIG_SETTING_MIN_YEARS_FOR_SHARES_HELPTEXT
+strval   = STR_JUST_INT
+cat      = SC_EXPERT
+
 [SDT_VAR]
 base     = GameSettings
 var      = economy.feeder_payment_share