Remove unused graph strings

data/language/en-GB.txt

@@ -1799,7 +1799,6 @@ STR_2450    :{YELLOW}Your advertising campaign for the park has finished
 STR_2451    :{YELLOW}Your advertising campaign for {STRINGID} has finished
 STR_2452    :{WINDOW_COLOUR_2}Cash (less loan): {BLACK}{CURRENCY2DP}
 STR_2453    :{WINDOW_COLOUR_2}Cash (less loan): {RED}{CURRENCY2DP}
-STR_2454    :{BLACK}{CURRENCY2DP} -
 STR_2457    :Show financial accounts
 STR_2458    :Show graph of cash (less loan) over time
 STR_2459    :Show graph of park value over time
@@ -3431,7 +3430,6 @@ STR_6356    :Spawns ducks if park contains water
 STR_6357    :Removes all ducks from the map
 STR_6358    :Page {UINT16}
 STR_6359    :{POP16}{POP16}Page {UINT16}
-STR_6360    :{BLACK}{COMMA32}
 STR_6361    :Enable lighting effects on rides (experimental)
 STR_6362    :If enabled, vehicles for tracked rides will be lit up at night.
 STR_6363    :Copied text to clipboard

src/openrct2-ui/UiStringIds.h

@@ -632,7 +632,6 @@ namespace OpenRCT2
         STR_COMPANY_VALUE_LABEL = 2227,
         STR_FINANCES_FINANCIAL_GRAPH_CASH_LESS_LOAN_NEGATIVE = 2453,
         STR_FINANCES_FINANCIAL_GRAPH_CASH_LESS_LOAN_POSITIVE = 2452,
-        STR_FINANCES_FINANCIAL_GRAPH_CASH_VALUE = 2454,
         STR_FINANCES_PARK_VALUE = 2787,
         STR_FINANCES_RESEARCH_TIP = 2275,
         STR_FINANCES_SHOW_CASH_TAB_TIP = 2458,
@@ -1247,7 +1246,6 @@ namespace OpenRCT2
         STR_CLOSE_PARK_TIP = 5296,
         STR_ENTER_NAME = 2791,
         STR_ENTER_NAME_INTO_SCENARIO_CHART = 2790,
-        STR_GRAPH_AXIS_LABEL = 6360,
         STR_GUESTS_IN_PARK_LABEL = 2223,
         STR_INCOME_FROM_ADMISSIONS = 2801,
         STR_NAME_PARK_TIP = 1720,