The graph illustrates the trends in marriages in the UK from 1951 to 2001, categorized into three groups: all marriages, first marriages, and remarriages.

1. **All Marriages**: The total number of marriages fluctuates, peaking around the early 1970s at approximately 450,000, then showing a gradual decline towards 2001.

2. **First Marriages**: This category shows a general decrease over the years, starting at about 400,000 in 1951 and dropping to below 300,000 by 2001, indicating a decline in the occurrence of first marriages.

3. **Remarriages**: In contrast, remarriages display an increasing trend over the same period, starting from around 100,000 and rising to approximately 200,000 by 2001. This suggests that while first marriages are declining, the rate of remarriages is increasing.

Overall, the data highlights shifting trends in marriage patterns within the UK over the 50-year span.