what is the total amount of players for the rockets in 1998 only?
{'header': ['Player', 'No.(s)', 'Height in Ft.', 'Position', 'Years for Rockets', 'School/Club Team/Country'], 'page_title': 'Houston Rockets all-time roster', 'section_title': 'R', 'caption': 'R', 'rows': [['Ratleff, Ed Ed Ratleff', '42', '6-6', 'Guard', '1973-78', 'Long Beach State'], ['Recasner, Eldridge Eldridge Recasner', '3', '6-4', 'Guard', '1995-96', 'Washington'], ['Reed, Justin Justin Reed', '9', '6-8', 'Forward', '2007', 'Mississippi'], ['Reid, Robert Robert Reid', '33, 50', '6-8', 'Forward', '1977-82, 1983-88', "St. Mary's"], ['Rhodes, Rodrick Rodrick Rhodes', '1', '6-6', 'Guard / Forward', '1997-98', 'Southern California'], ['Rice, Glen Glen Rice', '41', '6-8', 'Forward', '2001-03', 'Michigan'], ['Riley, Eric Eric Riley', '42', '6-11', 'Center', '1993-94', 'Michigan'], ['Riley, Pat Pat Riley', '42', '6-4', 'Guard / Forward', '1967-70', 'Kentucky'], ['Riley, Ron Ron Riley', '31', '6-9', 'Forward', '1973-76', 'Southern California'], ['Roberts, Stanley Stanley Roberts', '53', '7-0', 'Center', '1998', 'LSU'], ['Robinson, Larry Larry Robinson', '20', '6-3', 'Guard', '1993-94', 'Centenary'], ['Rogers, Carlos Carlos Rogers', '6', '6-11', 'Forward', '1999-2001', 'Tennessee State']]}