\documentclass{jarticle}
\usepackage{datatool}

\begin{document}

\DTLloaddb{scores}{studentscores.csv}

\begin{table}[htbp]
\caption{60\%以上取っているもの}\label{tab:topscores}
\centering
\begin{tabular}{llr}
\multicolumn{1}{c}{\textbf{姓}}&
\multicolumn{1}{c}{\textbf{名}}&
\multicolumn{1}{c}{\textbf{評点}}
\DTLforeach[\DTLisgt{\score}{59}]{scores}{%
\firstname=FirstName,\surname=Surname,\score=Score}{%
\\
\surname & \firstname & \score}
\end{tabular}
\DTLsavelastrowcount{\n}%
\n\ 人の生徒が60\%以上を取っている。
\end{table}

\begin{table}[htbp]
\caption{姓がBで始まる人}\label{tab:Bscores}
\centering
\begin{tabular}{llr}
\bfseries Surname &
\bfseries First Name &
\bfseries Score (\%)%
\DTLforeach[\DTLisgt{\surname}{B}\and\DTLislt{\surname}{C}]{scores}{%
\surname=Surname,\firstname=FirstName,\score=Score}{%
\\
\surname & \firstname &  \score}
\end{tabular}
\end{table}

\begin{table}[htbp]
\caption{”熊”で始まる人}\label{tab:Bscores1}
\centering
\begin{tabular}{llr}
\bfseries Surname &
\bfseries First Name &
\bfseries Score (\%)%
\DTLforeach[\DTLisgt{\surname}{熊}\and\DTLislt{\surname}{C}]{scores}{%
\surname=Surname,\firstname=FirstName,\score=Score}{%
\\
\surname & \firstname &  \score}
\end{tabular}
\end{table}

\end{document}
