Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Sport | Competition name | Competing entities | Age groups | Held every |
| --- | --- | --- | --- | --- |
| Aquatics | FINA World Junior Swimming Championships | Individuals [R ] | 17 or younger | Two years |
| Athletics | IAAF World Junior Championships in Athletics | Individuals [R ] | 18-19 | Two years |
| Athletics | IAAF World Youth Championships in Athletics | Individuals [R ] | 17 or younger | Two years |
| Badminton | BWF World Junior Championships | Individuals [D ] | 19 or younger | One year |
| Bandy | Bandy World Championships for Women U-17 | Nations | 17 or younger | Two years |
| Basketball | FIBA Under-21 World Championship for Women | Nations | 21 or younger | Only 2003 and 2007 |
| Basketball | FIBA Under-19 World Championship for Women | Nations | 19 or younger | Four years until 2005, now two years |
| Basketball | FIBA Under-17 World Championship for Women | Nations | 17 or younger | Two years |
| Basketball | FIBA 3x3 U-18 World Championships | Nations | 18 or younger | Year |
| Figure skating | World Junior Figure Skating Championships | Individuals | 13-19 | One year |
| Football (soccer) | FIFA U-20 Women's World Cup | Nations | 20 or younger | Two years |
| Football (soccer) | FIFA U-17 Women's World Cup | Nations | 17 or younger | Two years |
| Ice hockey | IIHF World Women's U18 Championships | Nations | 18 or younger | One year |
| Lacrosse | Under-19 World Lacrosse Championships | Nations | 19 or younger | Four years |
| Netball | World Youth Netball Championships | Nations | 21 or younger | Four years |
| Rowing | Junior World Rowing Championships | Nations | 18 or younger | One year |
| Sailing | ISAF Youth Sailing World Championships | Nations | Under 19's | annually |
| Sailing | ISAF Classes World Championship | Held in the Optimist, Splash, Zoom, RS Tera etc. | 19 or younger | Various |
| Speed skating | World Junior Speed Skating Championships | Individuals and Nations | 19 or younger | One year |
| Speed skating | ISU Junior World Cup Speed Skating | Individuals and Nations | 19 or younger | One year |
| Table tennis | World Junior Table Tennis Championships | Individuals [D ] and Nations | 18 or younger | One year |
| Volleyball | Women's Junior Volleyball World Championship | Nations | 20 or younger | Two years |
| Volleyball | Girls Youth Volleyball World Championship | Nations | 18 or younger | Two years |
Question:
what is the sport when the age group is 21 or younger and the competition name is world youth netball championships?
Answer:
Netball