Here is a summary of the seven times the S&P 500 saw consecutive annual declines in the index, including dividends:
1930: -25%
1931: -44% 1st time
1932: -9% 2nd time
1939: -1%
1940: -11% 3rd time
1941: -13% 4th time
1973: -14%
1974: -26% 5th time
2000: -9%
2001: -12% 6th time
2002: -22% 7th time
Source: Professor of Finance at the Stern School of Business at New York University, Aswath Damodaran; data series “Historical Returns on Stocks, Bonds and Bills: 1928-2022” updated January 2023: https://pages.stern.nyu.edu/~adamodar/New_Home_Page/datafile/histretSP.html